Sean “Diddy” Combs’ ex-girlfriend, Cassie Ventura, began what could be a days-long testimony in Combs’ sex trafficking trial Tuesday, alleging on the witness stand Combs had subjected her to physical abuse and coerced her to participate in “freak off” sex performances. (Here is a complete list of the allegations against Combs).

Prosecutors claim Combs coerced at least three women into engaging in sex acts with him and, at times, with male prostitutes, during occasions known as “Freak Offs,” where the women were allegedly dr...