I think part of that is that Jason was upset that Julie didn't call or text him--and honestly, I think she should have, it would have taken just a second and Jason could have planned accordingly. He still should accept that he can't run off and spend the night with MJ whenever he wants, however. IMO they were both at fault in that scene (and Jason of course had dealt with Joe's stomach issues, making him crankier).

BTW was Jason wearing Julie's bathrobe? I swear it was pink.