Is it looked down on for girls to wear pants suits?

I hate dresses, and skirts, but if I ever went somewhere with the guy I loved I wouldn't be sure what to wear. I'd like to wear pants suits, but he said he preferred his girlfriends to look famine, not that he knew I was referring to myself when I asked what he thought of them. I'd like to know what situations I should wear what, like if we went to a resturant, club, party, and any other you can think of. Also, guys, what do you think of pants suits?