We see again, AWALT. Slut putting herself in a situation to cheat on her boyfriend, then is "surprised" and "confused" when it develops into something more.
She's already shown she's not a classy broad, so treat her like the slut she is. Obviously you don't want to make her your girlfriend, but if you want her as a fuckbuddy just be decisive. There'll be a little hamster spinning in her head trying to make up reasons not to sleep with you, but she wants the D anyway, which is why she's been doing what she's doing and wants to have coffee with you. Ball is in your court now, Panagiotis. Success or failure depends on what you do next. Don't give up after the first or second or third reason she gives for why it's not a good idea or why she shouldn't do it, just sit there radiating testosterone like a failed North Korean Ubermensch experiment and kiss her again after you manage to hold eye contact for a while.