she slept with you straight away?
RED SIREN
probably rebound from her ex, girls who jump into things too quickly it's normally the case
some girls jump from guy to guy to get at the ones previous. and to escape the feeling of being alone where their ex probably is meeting with other girls, drives them and gives them the motivation to try and "create" a relationship out of nothing with the next decent looking guy they meet regardless of his personality. I think that's why they give them sex all of the time so they can keep them, until they are strong enough to be alone again or if things don't work out with them they move onto an easier target.
Its normally the ones who chase me I find are like this. Even if I never call them I receive countless text messages and missed calls asking me to come round and see them.
Girls like this personally I just ring them and be nice and a little patronising and say "alright, can you delete my number" and the response is normally "huh?" and so I say "can you, delete my number. and all of my messages, and clear the call register." then you get the "yeh" and then I say "alright, what, you gonna do that now?" ..."yeh", "cool, im goin ok" "ok bye" "bye"
Instead of the "doint ever call me again BITCH" thing which would cause an argument, I say it in such a calm happy way, and the girl responds in the same way and there is no bad feelings afterwards. and you don't hate each other, like in every other relationship ending.