India, May 15 -- Casandra "Cassie" Ventura claimed in her bombshell testimony that Sean "Diddy" Combs ruined her 29th birthday by forcing her into a "freak-off," New York Post reported.

"I told him I wanted to stay out and celebrate with my friends. In my mind, I didn't want to have the burden of doing that that night," Ventura said of Combs while testifying at Manhattan federal court.

The 38-year-old R&B singer told jurors that at the time she and Combs had gone to the Blind Dragon club in West Hollywood for karaoke with her friends, but he "pulled me out" of the event "so many times that I just gave up," per the outlet.

Ventura and Combs then went to attend a "freak-off," the disgraced rapper's infamous "drug-fueled sex parties." In ...