1 (22M) live with my roommate (24M), and we usually share food in the fridge without strict rules. The other day, there was one last slice of this amazing chocolate cake left. It had been sitting in the fridge for two days, and I thought it was fair game. Well, turns out my roommate was saving it, and when he got home and saw it was gone, he was furious. He said he had been looking forward to it all day and that I should've asked first. I apologized, but he wouldn't drop it, saying it was "selfish" of me. Now I'm wondering-should I have checked first, or was it fine since we always share food?

AITAH?