It's amazing how much shit you can get away with, verbally, when you sing to a girl. Imagine if you walked up to a girl and said, "I wanna put your legs on my shoulders... and make you scream my name." She'll most likely think you're a creep. Now imagine saying the same thing to the same girl, but this time you sing it. Odds are she will be smiling, blushing, maybe looking away because she can't handle the tension, etc.
And you don't necessarily have to know how to sing. I use to sound terrible when trying to sing, as if I was whining or something. After checking out some YouTube videos, I've definitely improved. I still don't sound good, but I don't sound bad. As long as you don't sound bad, you can pull this off.
Here's a video that helped me. Definitely check more of his videos out:
[youtube]
http://www.youtube.com/watch?v=Vrq-_zW_dNg[/youtube]
There you have it. You can now go out there and say some pretty perverted shit to a girl, but as long as you sing it, it's your free ticket to do so.