Why does he always do this?

My b/f is very y, he like lives in the gym (spends like 2 hours a night there, 6 days a week!) and is constantly eating protein bars and all that crap. Well for the most part he's a good guy, but when we are apart, he will constantly talk about his muscles and how his shoulders are "bigger then my body" and how his thighs are the size of an average 7 year old.. lol.. and thats when we're on the phone. In person I have to kiss his bicep 5 times an hour.. when we are fighting he will flex his pec muscles in his chest and say.. "look my chest is telling you to shut ur face" and stuff like that.. i've gotten used to it for the most part but why do guys do this? are all like this?