It means he is using you for sex without regard for how you feel. He's being selfish, and it's up to you to decide if a selfish man is what you want in life.

He's being honest with you. If you continue to have sex with him, you are agreeing to his saying that he's happy to continue sleeping with you, but has no intention of having a lasting, loving relationship with you.

I'd say break it off and find someone else.