The twosome step out March 8 to support Kardashian's stepbrother Brody Jenner at his girlfriend Avril Lavigne's album-release party in N.Y.C. So far, Humphries seems to be getting along with Kardashian's close-knit clan, in spite of sister Khloé telling PEOPLE the worst is yet to come. "He hasn't been to my mom's house with the chaos, so the initiation process will happen this summer – if he lasts," she says. "If he can get out of that alive, then he's good to stay."