Why am I so attracted to a certain scent?

I just love the way my bf smells. When I hug him his neck/chest areas give off a smell that I cant control myself with! It doesnt make me feel anything ual, but I'd say its sensual. I feel warm, happy, content....So I guess what I'm wondering is why this is, is it pheramones I'm getting 'high' off of or what? Does anyone have any links or info on this. Thanks!