Chances, if you, a female, are having sex with someone without love, it is for one of two reasons:
1. You like him, but he doesn't like you. So you are having sex with him in hoping that he will one day like you. As old saying goes, "Men give love for sex. Women give sex for love." The truth is, as long as you are having sex with him without being in a relationship, you are giving the milk without having to buy the cow. Men are not emotionally attracted to women who offer sex without love. Men will have sex with you and throughly enjoy it, but he will never love you. The more you offer sex, the more he will accept and give you the attention leading you to believe there is a chance. But the moment the sex is gone or he is tired of having sex with the same old body, he will leave you.
The bottom line, don't have sex too quickly. Make sure he likes you and respects you before you offer. If you offer too early, and he doesn't have to work for it, then he wil believe he doesn't have to work for much to get what he wants. If he lets you go because you didn't have sex with him, then he would have let you go even after you had sex with him. He was just looking for sex even and not a long term commitment.
2. The other reason why you, as a female, are choosing to seek casual sex is because you are seeking attention and is perhaps bored. Then one day, a man gives you attention and in return, you thank him by giving him sex or you just wanted sex at the time.
Generally, the other reason women offer sex is during times when she has low self-esteem and is seeking to boost her self-esteem. Men wanting to have sex with her is an indication that she is still wanted and she feels good.
There are other ways to boost your self-esteem. Do not use having sex with men as one of them becuase the truth is men, during casual sex, are only seeking sex and the attention given is canned.
In summary, realize casual sex is just sex with no other commitments or agreements. Do not believe or be hopeful there are future benefits because more likely than not, he will become less interested in you. Study shows the average man starts to get bored of sleeping with the same women after fives times. If you can accept casual sex for what it is, then you will be less likely hurt when he dates and commits to another women.