Not gonna lie, i have the same problem. I know bro, dudes just hit on her ALL THE FREAKING TIME. I've been dating my gf for about 1 year and honestly, when i notice this i stared working out cause i couldn't afford to have a stronger guy slap her ass and than get beat up. I beat up a total of 3 guys for been disrespectful. The worse thing is when she goes to the gym and EVERY FREAKING guy stares her in yoga pants. Sure i like it when she wears it, but i hate when other guys stare at it.
There is no solution bro, sorry. And yeah, its great to have her for le sexy times, but the thing is, you gotta always protect her from assh***s, no matter what.
[Edited on 01.01.2013 5:39 PM PST]