I think you are overreacting. He makes immature comments. All you need to do is tell him " look we're friends, but I don't like these sexual comments because I'm involved with someone else and you're making me feel uncomfortable, and I would appreciate it as a friend if you stop unwanted compliments".

That should be enough for him to get the message. If he persists with the silly remarks then cut him off as a friend. It's not rocket science what you need to do here. But getting worked up over his silly remarks isn't going to solve anything.