I think it's great. When I'm at fredericks, trying on lingerie to surprise me guy, I would absolutely love a male employee there to give me his opinion on whatever, whether it's too skimpy, too covering, too tight, whether it looks amazing or not.
However, most boyfriends would probably hate and envy the guy that works at fredericks that get to help the women with lingerie.
You'd definitely need to watch out for over protective boyfriends.
I'm in a very open, trusting relationship, I'd be able to come right out and say "Yeah, this guy that works at fredericks helped me picked this out, he told me the other one was too slutty (haha)." and my boyfriend would probably say "A guy works at fredericks? is he gay?" but from a girls point of view, it'd be pretty helpful, and you'd get to help hot chicks with lingerie, and the other men would think you're gay or the luckiest man alive.
I'm all for it.