I understand where you come from, but this instance underbelly feelings are definitely wrong. No good can come from this.

Also: think about what you think while you're in bed with the girl. What would you be thinking about the whole time? I wouldn't want to have my tools anywhere near someone that caused me so much harm. And there's a chance she ends up pregnant. Why even want to risk that?

Mate, you're wayyy too harsh here. Especially if it's a first relationship, this thing can become your whole world and you are willing to do anything to make it work. Blinded by love, OP said it himself.