I didn't even know this slut two mins and her clothes were off

I told my neighbour his sister was cute and she came in and closed the door. Then just takes her clothes off.i take mine off and even though she's not the greatest that whore tells me when she's horny she has to do it. Her sluttiness turns me on. We're dating but she's allowed to go with someone else if she needs it. We've been going out a month and she's already cheated twice. Says my dick is to small and when she met me she was dissociated.