The 27-year-old basketball player was trolled with a sign supporting Khloe Kardashian at the Cleveland Cavaliers' game against the New York Knicks at Quicken Loans Arena in Cleveland, Ohio, on Wednesday.
The game marked Thompson's return back home since reports surfaced on Tuesday claiming that he had been unfaithful to Kardashian. The 32-year-old reality star is still in Cleveland as she prepares to give birth to her and Thompson's first child together.
Kardashian has been a big Cavs fan since she and Thompson started dating in 2016, often spotted supporting her boyfriend on the court. "We [heart] Khloe," read a sign held up from the crowd at Wednesday's game.
Other fans in attendance reported hearing boos from the home crowd when Thompson took the court.
An eyewitness tells ET, “Whenever he appeared on the jumbotron, there was a lackluster response. A couple times when he came back onto the floor you’d hear faint booing or cheers, definitely not the welcoming he is used to from fans.”
"[Tristan] is usually a crowd favorite. He always gets a lot of love but tonight was definitely different. It was like the uncle who cheats on his wife, the family knows but no one directly confronts him. That was the energy surrounding him...awkward silence, disappointed stares, faint boos and cheering” the eyewitness said.
#Cavs fans booed Tristan Thompson when he was shown on screen. He wasn't announced coming off the bench by the PA announcer, either.
A source told ET on Wednesday morning that Kardashian has been "completely devastated" by the cheating allegations. "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," the source said.
Kris Jenner Flies to Be With 'Devastated' Khloe Kardashian Amid Reports Tristan Thompson Cheated
Kardashian also appears to have the support of her best friend, Khadijah Haqq, who shared a shady post seemingly aimed at Thompson's alleged infidelity on Tuesday.
Khadijah -- who alongside her sister, Malika, has been best friends with Kardashian for years -- shared a quote by legendary basketball coach John Wooden, which read, "the best thing a father can do for his children is to love their mother." The reality star captioned the post with a fist pump emoji.
Kardashian's sister, Kourtney Kardashian, liked the photo.