You don't. When a woman decides she wants more than just sex from you. There are two choices. Relationship or breakup.
You do understand that for women sex is the bait to get love/marriage/relationship.
Player Supreme said it and I've found it to be true. Eventually, if you are not going to be in a serious relationship, a woman you are seeing will "blow out". She's not gonna stay an FB forever and ever. A girlfriend is not gonna stay a girlfriend forever, she will eventually want marriage. And as we all know too many times married woman is not gonna stay married for ever anymore, she eventually wants out. Understand that all relationships are temporary, even in the only thing that stops them is death. Once you accept that, and you know what you really want. You understand more and you stress less. Good luck.