To add to cuckmecleveland's post, I'd say: don't overwhelm your girl with rules and your fantasy. A soft approach, but let her be the one to bring the subject up again. She will. Sharing your GF is a two way street, but she needs to feel she has a big say. It's her body that will be receiving his sperm and taking all the risks. THAT is what she may be thinking about. To make it work in such a fashion that she can relax and enjoy being shared, and secure in your existing relationship. Later you will have to give up some control so she can feel good and want to take those risks, all of which can have lifelong consequences. That's the critical factor that most boyfriends and husbands stumble on, they fail to see reality from their girl's perspective.
please add as much advice as you can give me , honestly feel desperate hahah , i want to see her with other guys and watch her eyes roll back as she creams over their big dicks