Just make sure she know's it's not an "expected" and go with it.... if it happens then don't fight it. If you fight too much she may get the impression that something else is wrong (like your not enjoying other things) and lose confidence. If your curious and she seriously wants too (for this you need a fully clothed converstaion) then give it a go... if your still not comfortable then don't go back there, but be open and talk!

CArl
xxx