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.

Freak-offs have become a central part of the government’s case, which charges Mr. Combs with sex trafficking, racketeering conspiracy and transportation to engage in prostitution. Mr. Combs has pleaded not guilty, and his lawyers have strongly denied that any of his sexual encounters with women were not consensual.

Sean “Diddy” Combs will have the support of his family as opening statements in his sex-trafficking trial are set to begin Monday in downtown Manhattan.