So much drama and you haven't actually got anywhere with this guy. And it looks like you won't get any further. If you can't deal with your friend with benefits sleeping with someone else, you have feelings for them. If you have feelings for someone and they don't reciprocate, you cease any sexual contact and basically back off for your own good. I think you kind of got the idea in the beginning, but it seems that you have not been able to let go of this guy and because of this you are not able to move on. I don't care how amazing the chemistry is between you: he knows how you feel, and if you were really right for one another you would have become an item a long time ago. I think you can feel so strongly about someone sometimes that your feelings delude you into thinking that you and the person in question have some special connection when in reality you just don't. He gets what he wants off you: sex and attention. Guys will almost always respond positively to sex and attention. They don't need to have feelings for you to do that. He knows you'll always be there in the background and he can take you or leave you. You're angry at him for his blow-hot-blow-cold behaviour, but maybe you should also be angry at yourself for rising to it every time. And let's be honest, your motivation for spending time with his cousin was to make him jealous. That's quite an extreme length to go to in order to try and evoke jealousy in someone, and if you were so convinced that you and this guy had potential, don't you think that spending so much time with his cousin would actually jeopardise your chances? You question his behaviour towards the end of the post and to be honest that's where you speak the most sense. He's not into you and he's certainly not acting like he is. There will be plenty of other guys who are into you. Let this guy go and meet some new people.