LOL!! ....tell you what I usually do in these situations.
First... I get fools drooling over my girl all the time too. I just laugh to myself because, deep down, these clowns wouldn't know how to handle a woman like this anyway, so they best off just looking.
....Now.....
There is always going to be someone else who looks better than you, or have more money than you, or have more women then you, etc etc. So if he hits on my girl, the first reaction is 'Obviously, this guys got good taste in women, but isn't very bright to be hitting on my girl in front of me.' After I evaluate everything, I remember what my Dad said to me one time.... 'You know what ILHM? We (Family Last Name) may not have a lot in this world, but at least we know how to f*ck!'
Then I feel all warm inside, and I proceed to have some fun.
...I flirt with second finest woman or women in the place, just enough so my g/f is reminded of who is REALLY Big Daddy in here, I do this so her attention is focused on me and no one else. It's silly but, hey, it's like some stupid instincts kick in or something, I dunno. I just know it works. Then if the guy touches her, and he knows I'm with her, I don't care how big your dumbass is, you're getting something for it. Honestly, I have yet to meet someone who knew she was with me, and attempted to get stupid about it.
Sometimes to know how serious a person is, you may have to kick a hole in them. Stand in their face and say, 'F*CK YOU!' ...they try to say something, stop them in mid sentence and say, 'F*CK YOU!' again... chances are, they'll back down from this after repeated, 'F*CK YOU!'s
....if they don't and swing at you, bust a bottle over their heads, and get the hell out with yo girl.
