She doesn't sound like too big of a slut. If she lets you do her anytime within the next week, she's a slut though. Don't feel bad though, it doesn't reflect on you. Most women, like most guys, are sluts. She's just not someone I would commit myself to.
Anyways, I bet you get nervous, can't get it up and when you finally do, you get about 2 thrusts in when you nut inside of her. And you will nut inside of her, because the first time feels too good to pull out. And you won't use a condom, because condom's suck and it's like a big iron guard around your dick.