My peeve is indirect spoilers, people think they're being slick implying things without saying them and then you can kind of deduce what happens. Even if you turn out to be wrong it ends up spoiling it because you were expecting a certain thing and if you call them on it then you are the bad guy for being too sensitive. I've asked people to just not talk about something at all and felt bad about it because I don't want to be telling people what to do but they just do it anyway so I've learned to just keep things I'm really excited about to myself until I'm done with it.