Rob Kardashian 'Furious' at Tristan Thompson for Cheating on Sister Khloe, Source Says

Rob Kardashian is reportedly furious at Tristan Thompson for putting his sister through a cheating scandal in the midst of her childbirth.

Kardashian, 31, has always been close with Khloe Kardashian. Last week, when Thompson was outted for cheating on her just days before she gave birth to their daughter, Kardashian was enraged at the NBA player, according to a report by PEOPLE. A source close to the family described him as "furious."

"Khloé has always been there for Rob and he hates that she was hurt — he knows what it feels like to be screwed over by someone you trusted," the insider said.

"Rob won't forgive Tristan for this," the insider added.

Kardashian isn't the only Kardashian to take the news of Thompson's infidelity hard. Another source told the outlet that Kim Kardashian and her husband, Kanye West, were also outraged.

"They both feel Khloé has gone through so much and that she deserves being happy," said the source. "They can't believe that Tristan has been going behind everyone's back. They find his behavior disgusting."

"Kim is very protective of Khloé and is especially upset," they added. "She can't imagine Khloé will stay with Tristan, but will support her sister either way."

Fans are dying for news on the future of Khloe and Thompson's relationship. Conflicting reports have emerged from numerous sources, saying at times that she is close to forgiving him, and at other times that their love is on the chopping block.

"Khloé really wants to be able to forgive and trust Tristan again and have the life she hoped to have with him," one source told PEOPLE earlier this week. "She doesn't know if she'll be able to do that, but that's the goal. She loves the life they had, she loves the baby they have together, and she still loves the dream of being a family together. If she can find a way to rebuild with Tristan, she will."

When Khloe announced that their daughter's name was True Thompson, many fans took the use of her boyfriend's surname as proof that she'd be staying with them. The insider said that, no matter what, Khloe wants True to have a positive relationship with her father.

"Khloé still very much loves Tristan, and this baby is one half his," said the source. "True is their child together. Giving the baby his last name was never in question."

Thompson was in New York City with the rest of the Cleveland Cavaliers last Saturday, preparing for a game against the New York Knicks on Monday night. He and his teammates were spotted in a Manhattan club, where multiple witnesses claim to have seen him kissing a strange woman.

Reporters later caught Thompson on camera returning to his hotel with the same woman in the early hours of Sunday morning. The stranger was spotted leaving alone a few hours later, carrying what appeared to be an overnight bag. Other videos of other indiscretions later emerged, dating all the way back to October.