If you wonder why men change after you sleep with them, the best answer might be that he didnt change: you did. During sex, your hormones caused you to feel both pleasure and a deeper connection to him. He possibly just felt pleasure. And, if you continued to have sex, this gap wouldve grown larger.

What changes after you sleep with someone?

Oxytocin (aka the cuddle chemical or the love hormone) is a chemical compound produced in the brain that prompts feelings of empathy, trust, relaxation and reduced anxiety. Levels of oxytocin rise when we make physical contact with another human being.