Hmmm, I would be totally fine with my boyfriend playing this game as well.
I'm even fine with him watching porn or going to a stripclub. Unlike too many girls I know, I'm not vain enough to think that my man will only look at me and never look at another girl. It's just not logical. It's all about the physical. So long as he doesn't act upon it I don't mind. No touching at stripclubs, no getting phone numbers, and no stuff that you wouldn't want me to do with another guy. Other than that, look all you want, be the character with the biggest juggs, stare, or even drool, I'm fine with that. At the end of the day it's me he is with. ^^
So, just tell your girl that you want to play and yes, the girls are hot, they are created to be that way, but you aren't going to leave her for a fictional character. If she can't accept that then....idk what to tell you. q.q