So, I was at a friend’s house, and they ordered a large pizza. I wasn’t very hungry but ate a slice or two. After everyone left, I stayed for a while longer and noticed that there were some leftover slices. No one else was there, and they had left the box open on the counter. I took the remaining slices. Later, my friend texted me saying I "should’ve asked first." Am I the asshole for eating the leftovers?