Tristan Thompson and Khloé Kardashian have been dating since 2016, and are days away from welcoming a child together

Tristan Thompson and Khloé Kardashian have been dating since 2016, and are days away from welcoming a child together. But amid new allegations that he’s been unfaithful, questions about Thompson have been arising again.

Originally from Canada and of Jamaican heritage, the 27-year-old athlete was drafted by the Cleveland Cavaliers in 2011 — at the time becoming the highest drafted Canadian-born player in NBA history to do so, The Toronto Sun reported.

His rookie season began with an NBA lockout, which allowed Thompson to finished up his college degree at the University of Texas (where he had previously played on the Texas Longhorns), Sports Illustrated reported.

Tristan Thompson Cleveland Cavaliers trainingCredit: Cleveland Cavaliers
Credit: Cleveland Cavaliers

He started as a center for the team in December 2011, according to his official stats, making his debut in a game his hometown Toronto Raptors. By season’s end, he had easily made his mark, becoming the first Canadian to ever earn All-Rookie team honors in the NBA.

Since then, Thompson has been a key member of the Cavaliers, playing alongside LeBron James and Kevin Love. In June 2016, the same season he re-signed with the team, Thompson helped the Cavs secure their first NBA Championship title in 52 years.

Khloe Kardashian And Tristan Thompson at LIV at Fontainebleau
Credit: Seth Browarnik/Startraks

“They’re really cute,” momager Kris Jenner told PEOPLE that month. “You know, she’s having a good time, he seems like a really nice guy. I think just with any relationship, just in life, I think it’s about chemistry and about values and about you know, about how two people get along.”

In December, Thompson’s ex-girlfriend Jordan Craig gave birth to his first child: son Prince Oliver.

Credit: Jerritt Clark/Getty Images

The baby-to-be, a girl, is due any day now. And it seemed like the couple was happier than ever, with sexy lingerie photoshoots and romantic Instagrams appearing left and right.

A source told PEOPLE in April that Thompson had been there for his pregnant girlfriend. “Tristan has been super supportive and very actively involved in everything that’s going on,” the insider said. “Khloé feels like she’s being treated like a queen. She doesn’t feel like he takes her or their future family for granted.”

I am so blessed to be creating beautiful monumental memories with such a wonderful man!” Kardashian wrote in a birthday tribute to Thompson on Instagram in March. “I hope this year brings you all that you dream of. You will forever be my always! I love you baby!”

Credit: Khloe Kardashian/Instagram

But it’s not all happy times for Kardashian and Thompson right now.

On Saturday, Thompson was allegedly videotaped getting close to an unidentified woman in a New York City lounge.

An insider confirmed to PEOPLE that Thompson was at the PH-D Lounge in Manhattan on Saturday ahead of the Cleveland Cavalier’s game against the New York Knicks on Monday. A man who has been identified as the athlete was seen speaking closely with a brunette in photos and footage published by the Daily Mail and TMZ. The Shade Room later published a video of Thompson and a brunette allegedly entering his hotel at 5 a.m.

TMZ also posted footage recorded in October 2017 allegedly depicting Thompson kissing one woman while a different woman groped him at the Darna hookah lounge outside of Washington D.C.

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Kardashian and Thompson’s reps did not immediately respond to PEOPLE’s request for comment, but a source told PEOPLE, “Tristan has been consistently cheating on Khloé. He’s a serial cheater. And there will be more women to come out of the woodwork.”

The source also said it’s a devastating situation for Kardashian. “First Lamar cheated on her and now Tristan,” the insider said. “She’s been through so much.”

“He was her everything,” a friend of the family added, explaining the Keeping Up with the Kardashians star “was beyond head over heels” with Thompson. “They had a life together. She honestly thought he treated her like gold, like a queen,” the source says. “[He] gave her everything, doted on her, told her how beautiful she was. To her, life was perfect. And it all just came crashing down.”

Credit: Khloe Kardashian/Instagram

Kardashian has been nesting in Cleveland with the NBA player as they await the arrival of their daughter. A source previously told PEOPLE she plans on giving birth there, and her famous family will fly in.

“I’m with Tristan and I get my home time — cooking, being with my love, and just more of a routine,” she wrote on her app and website. “In L.A., I’m SWAMPED with work. But then again, I love being in L.A. because I get to see my sisters and my mom, and I have my trainer and the people that I’ve grown up with. So there are perks to both cities for me!”