So me and my gf were talking to friends of ours last night who are also in a relationship. We explored the idea of having a foursome. This would involve only girl ongirl and guy on girl. The idea became pretty serious and it seems like this thing could happen real soon. I've thought about it alot since last night and I would be comfortable having sex with another girl in front of my gf, as well as seeing her with a guy, but I can't help but feel a little nervous about the whole situation. We've known this couple for a long time and we both trust them completely. So if anyone has experienced this before, please let me know what I am in for.