I usually don't take that much pleasure in enhancing a blow-job. If a girl wants to deepthroat, she will. If you're (men are) fucking whores, then be my guest. Slam her head down. If your girlfriend needs a little help opening up her tonsils, and she wants help, then by all means, help her. I can't remember the last time I had a blow-job, I was very much asleep this morning.