Because he's having sex with you. You are his sex partner. Congratulations.
The old chestnut about buying a cow when you get the milk for free is a trite, and frankly offensive generalization of the male psyche. However, it is exactly what this guy is thinking to himself whenever you have sex. He's probably invented a little tune he whistles in his head in time to your animalistic thrusts.
For many men (not all!), there is a pretty wide gap between liking a girl enough to make her a part of your life and liking a girl enough to put your penis inside of her. In other words, it sounds as if you've found yourself squarely in your man's Booty Call Zone.
The Booty Call Zone is essentially the male corollary to the Friend Zone. And sadly, chances of extrication for girls in the BCZ are usually about as good as they were for Gilligan and crew.
Perhaps he doesn't mention you to his brother because of a particular aspect of your relationship he finds embarrassing, like a complication at work or his many wives. But far more likely, he just hasn't upgraded you to girlfriend status in his mind, and he's not about to make his relations learn your name when he expects things to either continue as they have been or dissipate in the near future.
If you're enjoying the sex, by all means, have some nice fun sex. If you're looking for something more, it might be time to look elsewhere.
why why why?? why do girls do that ALL the time??
dude! if you let him see you naked and then he doesnt return your phone calls for a week and when he DOES get back to you, there is always a stupid ass excuse bout his cat/work/grandma/school..you probably should savour them great 14 seconds in your head and remember him fondly as an ass hole.
a guy will always introduce you to his friends (if he is proud of having you in his life)..always call you and ask about your day (if he cares about you) and NEVER call you just for sex.
is it really something you have to explain??
Hooray for the concise truth. Nothing could say it better than those first three sentences.
@nono: It seems like you were thinking along the right lines, but you must've missed the part where she said she sees him every day.
Being a sex buddy when you really want more sucks. I feel for you. TALK TO HIM!
@ TheMetalHead re: nono reply:
Add to that another useful cliche: "Never shit where you eat."
I'm in that situation right now. Thanks for the insight.
I have recently found myself in the same situation. My friends with benefits calls me everyday and not just for sex. We actually talk about our lives. He recently introduced me to his friend, and he introduced me as his sister's friend? WTF!?!? I'm good enough to sleep with and talk to everyday but not good enough for a commitment. It is definetly hard not to get attached emotionally to your friend with benefits..
i'm going to copy and paste my answer from another question.. because i feel that it is that good =-)
Guys can have sex without having feelings. Girls cannot separate the two if there are any feelings there in the first place on your end. Guys have the ability to just have sex with you repeatedly and not give a damn (or at least just not have those feelings for you). You may think you're being the "cool girl" that can have sex with him without things getting messy.. but if you like him and wan it to be more, then you have to end it. I know from experience, if he does not return the feelings (which he obviously does not since he has not asked to date you), then it will break your heart when he finds someone else and drops you in a second- which he will. It hurts like hell, and they can't understand it because they can separate their feelings from booty calls. He doesn't want you, or else he would ask you out again. My very heart felt advice would be to break it off if you are waiting for him to wake up and realize that you're the one for him. Chances are that he won't and you'll be wasting your life waiting for him. I promise, because i did it for a year.. my my heart broke in a million pieces a few times over this ass hole who said all the right things to elude to the fact that we MIGHT get back together one day.. anyway.. lol i'm very passionate about this. No booty calls. Guys can't understand it, he just wants you for sex until something else comes along.