Often that is the case. Either fixed or birth control.
I'd like to find a fertile guy (wherever we go on vacation, as this is still in thought stage), and have him fuck my girl and cum in her. She isn't on birth control
He must likely is serious. He doesn't know if you are. Take an active role in bringing it up. Start dressing more provocatively at home and when you go out. Get details in what he's wanting to do. Go from there