Why do you think this is? (Women only answer.)?

I am a decent man, hard working, & 18. Why is it that I always seem to fall for my closest friends? I could have no interest in a woman, but after we have been friends for a while feelings will begin to develop or I will fall for a woman and somehow end up screwing myself over into the friend zone.So it's been almost a year now since my last girlfriend, but I have loads of friends that are girls. It's hard to explain it any better than that. Also any woman I date no matter her personality before I date her always turns into a slut after I date her. Like my last ex was a church girl and now she is quite promiscuous and I honestly did not intend for that to happen. Why do you think that happens to every woman I date. I mean I'm always a decent guy in a relationship and make no emphasis on , but yet this oddity still occurs.