My girlfriend would know better to not touch my games....
...if I had a girlfriend, of course.
I wouldn't have this problem because whenever I meet a girl, I give here two facts she needs to know:
1. Don't touch my video games, ever.
2. I ain't no bitch! And I ain't gonnna take no shit from you, so don't get out of line.
If she stays after I've said that, then I'll know she's a good one...none of them have stayed so far though.