I just Googled and found this:
9 Common Reasons Men Disappear After Sex
1. He’s embarrassed.
Men feel pressure to perform sexually, and the first time is the worst. He doesn’t know what you like or what you don’t like. Everything is new, and if he likes you, then he really wants to “rock your world.” But if something doesn’t “go up” at the right time, or if something else “comes out” too soon (if you know what I mean), then it can be really embarrassing. Most guys won’t want to think about what you will tell your friends. He might even assume you don’t want to see him again. No matter what you said, when you were with him. Maybe he will even avoid you, and never call you back.
2. He is a weak communicator.
About 50% of guys report being “shy” in some situations. And calling a girl to say, “I don’t think it is going to work out between us” is one of those situations. It is even harder after having sex. For a shy guy, it is a lot easier not to call.
3. He doesn’t think he has to.
He knows he should call, but he doesn’t feel obligated. Most guys aren’t sure what they are doing with women. The “dating rules” have gotten so complicated. This makes it easier to avoid doing what they know is the right thing to do. Often guys tell themselves, “A lot of girls have never called me back again, so…” Not right, but true.
4. He fell in love.
Every day people fall in love. Every day people find someone who they are really compatible with. Maybe he just found the girl of his dreams? This happens more than you think.
5. He wasn’t into you.
Most men will sleep with a larger selection of women, than they would agree to date exclusively. Maybe this has to do with the thousands of years, men spent evolving traits to effectively spread their genes. Or maybe it has to do with our cultural norms that say it is
6. The mystery is gone.
Sexual tension needs mystery to survive. If you’ve shared too much about your life, you could have killed the mystery. I’m not saying to be a complete mime and avoid talking though. Here are few things to avoid mentioning at first:
- Your insecurities
- Details about past lovers
- Reasons it didn’t work out with other men
- Feelings you have for other guys
Men and women both enjoy a challenge, and it is healthy to have boundaries about what you share. Wait, before sharing too much about yourself.
7. It is too soon.
Like I said, men and women both enjoy a challenge. If you are too easy to get, he will assume that you are not very valuable. This is how the human mind works, according to psychological studies. Unfortunately, each guy has a different time frame in his mind about sex too. This means you can’t predict when the right time to sleep with him is, but you can focus on only sleeping with guys, when the time is right for you.
8. Not his type.
Everyone has different tastes and preferences. Some people like classical music and others are into hip-hop. Being sexually compatible is important to most men and if he wasn’t feeling a connection, then he might not call back.
9. He’s a good liar.
Some men lie to get what they want. “Wanting a relationship” is a common lie men tell, when starting to see a girl. Or maybe he exaggerated his feelings for you. In rarer cases, he may be dating someone else. Either way, you are lucky to be away from him.