Cassie Ventura testified against Sean "Diddy" Combs in a federal trial, detailing alleged abuse and her role as a star witness in the sex crimes case.

On the stand in court Tuesday, Cassie alleged Combs would "bash my head, knock me over, drag me, kick me, stomp me in the head if I was down."

Casandra "Cassie" Ventura is opening up about why she participated in the "Freak Offs" — hours-long sex parties where she alleges her former boyfriend Sean "Diddy" Combs forced her into sexual activities with other men.