Gene Maddaus Senior Media WriterJohnny Depp repeatedly hit Amber Heard in the face during an argument at the couple’s penthouse in March 2015, Heard’s sister told a jury on Wednesday.The sister, Whitney Henriquez, was called to the stand to corroborate Heard’s allegations that Depp repeatedly assaulted her over the course of their four-year relationship. Heard is defending herself from a defamation suit brought by Depp in Fairfax, Va.Henriquez described witnessing a fight in which Depp and Heard were screaming obscenities at each other. Depp ran upstairs toward a mezzanine and hit Henriquez in the back, she said, and then Heard smacked him, saying “Don’t hit my fucking sister.” Depp’s security guard then ran up the stairs.