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).

Ventura, who is the prosecution’s star witness, testified last week that she endured physical and sexual abuse from Combs and detailed how he orchestrated drug-fueled sex performances called “Freak O...