No I think I will refer to you as 'girl' from here on. Seriously though after six years, there's not much chance I don't think; the best options are probably 69 or explaining how you feel to her.
Ok what tuc said would be another approach but then you would be castrated because im guessing shed bite it off. Note to self...do not ask tuc for a date.
I said it before and I will again. This is why you keep your thumb over one of her eyes. If she bites you, then you gouge her fucking eye out. She'll think twice before she bites you again.
Shit, some chicks just don't like giving head. After 6 years you're both probably comfortable with each other....sorry dude, I don't think she's gonna be heading south anytime soon.