dude, it's been an hour. you really can't just blurt out "HI! " now. get up to go to the bathroom, or if there isn't one, get something from a bag or whatever. when you're coming to sit back down, "notice" the shirt. "ha is that a reddit shirt? I'm on there way too often. " if she says yeah and nothing more, it's fine. else, just let it flow. 