When we make out, she bites a lot and now my lips are swollen. How do I

talk to her about this? Sometimes when we make out for a long time, my lips hurt afterword. She likes to bite a lot. Like a lot. She'll bite from the start to the end. It feels good, she never makes it hurt, but when I wake up the next day, I guess my lips are just irritated from all the scraping from her teeth. Sometimes if my lips are wet and I lick them, I could taste a little blood. I want to say something about it, but I don't want to ruin this for her. She really likes to bite.

What should I do?