So my bf has been talking a lot

About having a foursome with his friends. One is a guy one is a girl. This is something that I have fantasied about but I don’t know if I can bring myself to do it. I want to but don’t want to. The big thing is I don’t want to share him. I don’t think I’ll be able to stand seeing him with another chic. I don’t want anything to change between the two of us afterward or him start wanting this to happen all the time. Second I am shy it’s hard for me to just let loose. Now with him and I in the bedroom it’s amazing I get into some kinky stuff. Then I also think about my body and I’m afraid I’ll feel insecure with the other chic who I have never even met. So many things going through my mind!! It definitely turns me on thinking about doing it but can I actually go through with it. So what are thoughts and maybe some pointers on how to calm myself and

Just go with the flow. I have expressed all of my Worries with him also.