During their relationship, they've talked about the possibility of marriage, expressed their desire to start a family -- which they did in April, when Khloe gave birth to their daughter, True Thompson -- and had nothing but love and praise for one another in interviews and super sweet social media posts.
Though they've hit a bumpy patch, ET looks back at the couple's whirlwind romance and the sweetest things they've said about one another since the start of their PDA-packed romance.
August -- Sparking Rumors
Khloe Kardashian and Tristan Thompson first sparked romance rumors after they were photographed leaving the Los Angeles nightclub Bootsy Bellows within minutes of one another.
Earlier in the evening, Khloe and Tristan were joined by Kourtney Kardashian and family friend Jonathan Cheban for dinner before heading to watch Kanye West perform at the American Airlines Arena as part of his Saint Pablo Tour.
Khloe traveled to Cleveland to support the Cavaliers star as he accepted his NBA championship ring. The reality star -- who rocked a green coat with a fur stole and thigh-high leopard-print boots -- shared photos of the special occasion to social media.
Khloe's Storm costume was spot on, complete with platinum-white hair and glowing eyes, while Tristan's athletic build gave a real believability to his Black Panther outfit. Plus, the pair weren't shy when it came to making out on the dance floor at the huge Halloween night bash.
"I live here, but I’m there very often," she told Kimmel of splitting her time between L.A. and Cleveland. "I actually really do [like spending time in Cleveland]. I actually really like it. I like just having my routine and being a little more under the radar."
"My boyfriend’s a cutie, so I do like big men," she admitted. "I love athletes. Someone who has the same interests as me, who likes to work out, like that’s their hobby or their job, that’s fine… Tristan is who I’m into. He's a little cutie."
Dec. 19 -- Tristan's First Baby
Amid Tristan's burgeoning romance with the KUWTK star, he also became a first-time father when his ex-girlfriend, Jordan Craig, gave birth to their son, Prince Oliver. The couple split up shortly before he struck up a relationship with Khloe, while Craig was pregnant.
The happy couple spent their first Christmas together, with Tristan taking to Instagram to celebrate the happy holiday. He shared a photo of himself and his lady love in luxurious fur coats, writing, "Merry Christmas & Happy Holidays from me and mines, to you and yours."
The couple got close on the dance floor as they rang in the new year together at Nicki Minaj's performance at E11EVEN nightclub in Miami. Khloe posted a steamy snapshot from the celebration, showing her grinding up on her man while rocking a shimmering gold-sequined gown. "Happy New Year!!! May you always be surrounded by the love you are deserving of!" she captioned the pic. "May Gods blessings continue to rain on us all!"
Khloe showed just how much she adored Tristan when she threw a glamorous house party to celebrate her boyfriend's 26th birthday. The house was filled with sparkly gold balloons as well as giant letter balloons that spelled out "Happy Birthday," and the table was set with a stunning floral arrangement that served as a table runner. The decadent spread also included donuts with glitter sprinkles, golden Kit Kats, and cookies with the couple's picture on them.
She later took to Instagram to send her beau a sweet message, writing, "To the happiest of birthdays my love! To the first of many more together! May God continue to bless you in all of your days! And may we forever look at one another like this 💋."
"We’ve talked about it. He [already] is a father, and I know for a fact that he would be an impeccable father," she said. "I definitely want to be a mom. But I don’t put the pressure on it. It’s not like, 'the clock is ticking.' I feel in my soul it will happen."
She also said she would say yes if Tristan popped the question, adding, "[I've] never been in this type of love."
Three months after Khloe threw Tristan a special b-day party, her boyfriend returned the favor with a surprise celebration with tons of her friends and family at the Blind Dragon restaurant in Los Angeles. Tristan went all out for the big night, covering the club in decorations and golden treats, and they even had a photo booth.
August -- 'Best Relationship Ever'
Khloe opened about her romance with the Canadian basketballer in an interview with the Mail on Sunday's YOU magazine, once again talking about the possibility of getting married again and starting a family. "I’m in the best relationship I’ve ever been in and it doesn’t take a ring for me to feel that way,” she said. “I believe in marriage and I want to be married again one day but I don’t have a time frame. Why do people think that marriage equates to happiness? There are a lot of people in unhealthy marriages.”
Meet Tristan Thompson: Everything You Need to Know About the Father of Khloe Kardashian's Baby
Khloe also noted that their relationship works well and stays strong because they share the same "belief system and morals," which makes dating and communicating easier. She went on to say that Tristan is "very protective" of her, adding, "Feeling loved and validated and secure is a huge thing. Tristan is protective of my entire family, which is beautiful. And I love that everything we do is as a union. When he speaks, it’s ‘us’ and ‘we,’ and that’s important because it shows that you’re sharing life."
September -- Pregnancy Rumors
Reports first surfaced that Khloe and Tristan were expecting their first child together just days after it was revealed that her younger sister, Kylie Jenner, was pregnant. A source told ET at the time, "Khloe is pregnant and due early next year. It's going to be a very busy time for the Kardashian-Jenner family… It's no secret that Khloe was eager to become a mother. This is something she has wanted for a long time and finally the timing is right."
Khloe finally confirmed the pregnancy rumors when she took to Instagram to share the news alongside a photo of her bare baby bump, cradled by her and Tristan's hands. "My greatest dream realized! We are having a baby! I had been waiting and wondering but God had a plan all along. He knew what He was doing. I simply had to trust in Him and be patient. I still at times can't believe that our love created life!" Khloe wrote. "Thank you to everyone for the love and positive vibes! I know we've been keeping this quiet but we wanted to enjoy this between our family and close friends as long as we could privately."
“For six months [pregnant], you a fine six months, baby. I’ll tell you that," Tristan flirted in a sweet Snapchat video from the couple's New Year's Eve night out in Ohio.
March 4 -- Gender Reveal
As part of the Keeping Up With the Kardashians season 14 finale, Khloe first revealed that she was expecting a little girl while talking with her sisters. She also took to Twitter to address the news, and sweetly gave a shout-out to Kylie Jenner and Kim Kardashian West's newborn daughters, Stormi and Chicago.
I am now so excited my daughter will have forever best friends with Chicago and Stormi!! God is great!!! Thank you Lord for our princess 👑 👶🏽💗
"I am now so excited my daughter will have forever best friends with Chicago and Stormi!! God is great!!! Thank you Lord for our princess," Khloe shared.
March 11 -- Baby Shower
Khloe and Tristan went all out for their baby shower, a stunning pink-filled soiree held at Hotel Bel-Air and hosted by Amazon Baby Registry. In the pics, there are hundreds of rose-colored balloons on the ground with pink flowers dangling from the ceiling, pink table settings and lighting. There was also a neon sign that says, "Baby Thompson."
In a Snapchat video, Khloe shared, "I'm so excited it's my baby shower," while Kendall Jenner cuddles up to her and rubs her baby bump.
April -- Countdown in Cleveland
In the days leading up to her due date, Khloe spent her time keeping a low profile, relaxing at the couple's home in Cleveland and taking to Instagram and Snapchat to document the final days of her pregnancy journey.
The 33-year-old reality star, who has never shied away from baring her glowing pregnancy bod, posted numerous artistic photos of her baby bump in romantic snapshots with Tristan. On April 9, Khloe posted a touching photo of her and her shirtless boyfriend sharing a sweet kiss, which she captioned, "We are ready whenever you are little mama."
"The video going around showed Tristan in a loud club briefly talking to a girl, nothing more," the source says. "Tristan was there for roughly an hour and left with his teammates. Khloe and Tristan are happy and focusing on the birth of their daughter."
In the wake of the reports, TMZ also published a video of what appears to be Thompson kissing and getting cozy with two women at a hookah lounge outside Washington, D.C., in October 2017. The NBA star didn't comment on the reports.
April 11 -- Khloe's Family Comes to Comfort Her
A source told ET that Khloe's family was standing behind her to lend emotional support as she approached her due date, amid reports that her boyfriend, Tristan Thompson, has allegedly been unfaithful. "Kris has gathered the family and made sure they would all be there for her," the source said at the time. "They are so excited for Khloe. Her sisters are being super supportive of her… her family is rallying around her."
The source said that despite photos and videos published by multiple outlets that allegedly show Thompson being intimate with unknown women, the family was trying to make sure Khloe focuses on the thing that matters right now, which was the birth of her daughter. Meanwhile, another source said that Khloe was "completely devastated," explaining, "Tristan is a man Khloe built a life with and saw as her forever. Khloe’s mother, Kris, flew to Cleveland to be with her and support her in whatever she needs."
April 12 -- Khloe Gives Birth
Amid the cheating drama, the couple welcome their first daughter together, a baby girl, around 4 a.m. ET in a hospital outside of Cleveland, Ohio. "Baby and mom are healthy,” a source close to the Kardashians told ET, adding that the little one is "beautiful."
"Our little girl, True Thompson, has completely stolen our hearts and we are overwhelmed with LOVE. Such a blessing to welcome this angel into the family! Mommy and Daddy loooooove you True!" the new mom wrote on Instagram.
Then, two weeks after True's birth, Kim Kardashian West described the infidelity scandal as "so f**ked up" during an appearance on The Ellen DeGeneres Show. "Like, I don't even know how to describe it. It's just so f**ked up," she shared. "We really were rooting for Khloe, and we still are," the mother of three continued. "She's so strong and she's doing the best that she can. It's a really sad situation all over."
May 4 -- Khloe and Tristan Step Out
The reality star and basketball player were spotted enjoying a meal together with a few friends at TownHall restaurant in Cleveland, Ohio. Photos and video obtained by TMZ show the Good American designer looking relaxed as she smiled at the table sitting next to Tristan.
May 6 -- Khloe Supports Tristan at Cleveland Cavaliers Game
The new mom stepped out to support boyfriend Tristan at the NBA star's playoff game. Khloe was escorted by security as she sported sunglasses and a leopard-print dress, heading into the Quicken Loans Arena in Cleveland, Ohio, in a photo obtained by TMZ.
May 7 -- Kris Says Khloe Is Doing 'Really Good'
Khloe's sisters and mother, Kris Jenner, hit the red carpet at the Met Gala in New York City, and ET spoke with the momager about how her daughter was doing following Tristan's cheating scandal and the birth of her first child.
Met Gala 2018: Kris Jenner Says Khloe Kardashian Is the 'Best' Mom (Exclusive)
May 9 -- Tristan Opens Up About His and Khloe's Baby Girl
Tristan stayed mum about the status of his relationship with Khloe in an interview on UNINTERRUPTED's Road Trippin' Podcast but had no problem sharing details about his daughter. "She's doing good," he said of the newborn. "Baby True is eating, sleeping and, uh, sh**tin'."
May 10 -- Kim Says She's Rooting for Khloe and Tristan After Being Blocked on Social Media
Khloe's older sister dropped by Live With Kelly and Ryan and was asked how her sibling is doing since reports surfaced that Tristan cheated on her.
"Yeah, I mean, last time I went on TV and I answered some questions about her, I got blocked on social media, so..." she revealed, though clarified that she wasn't blocked by Khloe. "So, yes, I'm going to ... yes, I'm always rooting for her, always rooting for love. I'm always rooting for family."
May 13 -- Khloe's First Mother's Day
The new mom was basking in the joy of her first child after she turned one month old a day prior to Mother's Day. Khloe gave fans a first glimpse of True on her milestone one-month birthday, with fans quickly cooing over the newborn and trying to figure out if True looked more like her mom or dad. "Tristan and True are twins lol it’s crazy," Khloe told one fan.
Everyone tells me they are identical lol it’s wild maybe her eyes will stay light and I can get something lol