M y former girlfriend used to go nuts when I bit her neck or kissed with a lot of suction during sex. I tried this on my new girlfriend and she'd have no part of it. One of my nibbles left a hickey and she treated me as if I were some kind of sadist. Maybe that's why high schools are frequently mistaken for leather bars. We happen to think that love bites are the accent marks in the language of lust.
Suction equals passion.
But not everyone agrees. The rest seem to side with your girlfriend.