Deep down i only act nice to girls cos of an unconscious desire for sex

I get along better with girls than with guys. But when I think about it I'm just much more cold around guys. I'm not mean or anything, I'm just nowhere near as friendly or sympathetic or helpful (and it's not because I banter with them or anything either, I'm not really into all that). I really empathise with girls when they're feeling happy/sad, and I always go out of my way to help them. I don't purposely do all of this with the intention of eventually seducing them, most of them have boyfriends anyway. But I've rarely ever met a girl that I haven't wanted to fuck, and so I think my brain just tells me to act really nice to them with the imagined remote possibility that it will eventually lead to sex and possibly a relationship. And it's not just with girls I have a crush on either, it's all of them. I'm not ashamed that I'm attracted to them and want to have sex with them, there's nothing wrong with that. I just worry because they all insist I'm really nice and sweet but really it might be because I want something in return, because I'm just selfish looking out for myself. Plus then I'm worried that I don't even see them as people, that I just see them as opportunities.