Sean “Diddy” Combs’ former girlfriend, the R&B singer Cassie, told a jury Tuesday that the music mogul abused and sexually exploited her for years, as she took the witness stand for the first time during his sex trafficking trial in New York. Sighing heavily and pausing to compose herself, Cassie recounted feeling compelled by Combs to participate in lengthy “freak off” sex parties involving male sex workers. She said Combs assaulted her numerous times during their turbulent relationship.