I've lived with women, you're looking too deep into it. They do these things, the only reason I would say maybe, just maybe, she's up for it, is her age. She goes to school with teenie boppers, they probably think she's an adult in school, and the same way they view her, in the real world, she views you (an even older person).
18-20 year old chicks are trying so hard to get to that level of adulthood and live the life they see on TV. So she might be thinking about it on a fantasy level, but she won't make a move in fear of your gf (an older alpha woman). trust.
Just flirt for fun, it's always nice to have that around for your ego, but don't drive yourself crazy thinking about sex. Itll ruin your relationship.
edit: she's a 19 yr old stripper?
She's mentally unstable. If shyt hits the fan, she'll burn your clothes nikka. stop thinking with your dikk.