My partner really wants me to cuck for him. He suggested we make a dating app profile for it to find guys with big equipment to have sex with me whilst he watches. He wants them to climax inside me and everything. The thought turns him on so very much. But I am demisexual and he is my whole world. I am also massively monogamous when it comes to sexual relationships. He doesn't want to share himself with anyone else, he just wants to share me. What should I do?