Sean Combs: Victim-4 takes the stand.

A woman who worked as Combs's personal assistant testified -- under the pseudonym "Mia" -- that he once had her work five days straight with no sleep, threw things at her, including a laptop and an ice bucket, and that he sexually assaulted her. On the stand she said an "irate" Combs once chased her and Cassie Ventura onto a Caribbean beach and that they paddled out into the ocean to get away from him, but the weather turned. "I was trying to weigh if it was scarier to face mother nature or to go back to Puff," she said. "Mia" testified that she never told anyone Combs was allegedly sexually assaulting her. "I was going to die with this," she said. "I didn't want anyone to know ever."If you want to read NBC's coverage of the trial, check out our newsletter, “Diddy On Trial”: NBCNews.com/Diddy