Kid Cudi took to the witness stand on Thursday to testify at Sean 'Diddy' Combs' sex-trafficking trial. Cassie alleged that Diddy reacted violently when she and Kid Cudi had a fling in 2011.

Kaplan, as previously reported, is alleged to have worked for Diddy as an assistant for a period of about two years. One day prior, Kaplan testified that part of his duties included cleaning up the locations where alleged "freak-offs" took place,

Amid her on-and-off relationship with Diddy, Cassie had a brief romance with Kid Cudi. Here's everything to know about Cassie's relationship with Kid Cudi, including why he is now testifying at Diddy's sex-trafficking trial.