NBC affiliate WKYC snapped a photo of the NBA star — which you can see here — stepping out of his car on Thursday.
Entertainment Tonight reports Thompson was at the hospital while Kardashian was giving birth, but it has not yet been confirmed if he was in the delivery room.
The 33-year-old reality television personality gave birth to her first child around 4 a.m. Thursday morning.
The birth comes just days after the Cleveland Cavaliers player was caught on camera kissing a mystery woman and going with her back to her hotel room. A second video leaked out of Thompson with two women kissing at a club in October.
Despite initial reports of Kardashian being devastated by the scandal, but reports began coming out as early as Thursday that Kardashian was willing to stay with Thompson.
"She's a hopeless romantic and she'll try to make this work," a source told PEOPLE. "She tried forever to make it work with Lamar [Odom]. She's having a child with Tristan, and she's going to try to rebuild this," they said.
"Khloé could probably convince herself to get over the fact that he maybe, kind of, sort of, hooked up with some groupie while out on the road," they added. "But being so indiscreet about it and letting it get splashed all over the place and having it humiliate her? That's actually even worse."
Sisters Kim and Kourtney Kardashian, momager Kris Jenner and best friend Malika Haqq were all confirmed to be at the hospital at the time of Kardashian's delivery. TMZ reported on Thursday prior to the birth that she was allowing Thompson to still be in the delivery room, and the reported was later echoed by The Blast after their yet-to-be-named daughter was born.
According to In Touch, the NBA Champion has been in Kardashian's ear ever since the news broke, begging her for forgiveness.
"[Tristan]'s been in Khloé's ears apologizing, telling her that these videos aren't what they look like," the source told the tabloid. "He's telling her that the girl he was with at the hotel is [a friend of a friend] and that the video of him kissing that chick last year was a stupid bet he made with one of his teammates."