You fall into the category of my buddy then....can let things slide. You are right though, but still not sure I could let it slide as easy. Well I know I can't because I had something similar happened and I didn't take the high rode.
They way I gain muscle mass is by gaining weight, then leaning it. Some idiot I don't know walks into the locker room as I am changing and says "don't you usually have a 6 pack". I am like "well sort of but I am in my gaining phase now, so I'll lean it out later". So he comments "yeah you have a big gut now". I got annoyed and said "well still not as big as yours though". then gave him a angry look. The guy won't even look at me now Good though as people need to learn to not talk like that to people they don't know. Honestly 5 years ago I'd of told him to "f*ck off" so that really was progress to me.