Sean “Diddy” Combs reportedly made Casandra "Cassie" Ventura refer to him as “Pop Pop” — the name she called her own grandfather. Ventura, who is 17 years younger than Combs, testified in court on Tuesday, May 13, about her years-long relationship with the music mogul who's now on trial for sex-crimes and racketeering.

Read the latest news on the Sean "Diddy" Combs' trial in New York. Cassie Ventura, Combs' ex-girlfriend, took the stand as the government's star witness.

Lawyers on both sides of Sean Combs' sex-crimes trial delivered opening statements, and witnesses alleged the one-time mogul was violent in multiple instances.

Cassie Ventura, a longtime girlfriend of Sean "Diddy" Combs, said she loved the hip-hop mogul and felt a sense of duty to join "freak offs."

After being chosen during jury selection just this morning, jurors have already heard opening statements and witness testimony in the trial of music mogul Sean "Diddy" Combs. Here's a recap of what happened in court today.

Ventura Fine alleged Combs would "bash my head, knock me over, drag me, kick me, stomp me in the head if I was down."

The federal sex trafficking case against Sean “Diddy” Combs began with disturbing and graphic testimony from a key witness. Daniel Phillip, a 41-year-old escort, testified that the music mogul paid him large sums to perform sexual acts with Diddy's ex-girlfriend, Cassie Ventura, while Diddy observed and gave directions.