Girlfriend's fantasy

My tiny, sexy, hot girlfriend has some crazy fantasies and I wonder how normal these things are. She is bisexual and has an incredible sex drive, which is perfect for me. I tell her I would love to get it on with another girl and her so I can watch and maybe join in. She is all for it, but she wants me to do something that I wasn't ready to hear. She said her and her girlfriend love to see guys giving each other head eat and share the sperm with them. She also has a wicked cum fetish. I said I would think about it. Although I'm totally straight I have wondered what it would be like.I've wished I could reach my own for as long as I can remember. So I wondered if any other girls out there can relate. It seems so taboo that it kinda turns me on. She said they would like to role play and make me do stuff, just head..No Poopshoot stuff, I don't like that, even with a girl. I guess with the right buzz and dim, dim lights I will submit to her wishes and oralsex commands. I've got some wild senerios played out, because they are both pretty girls with petite hard bodies. I'm excited and scared at the same time. Well I suppose, for now, it's ready or not here I cum. Any suggestions???