My girl and I have tried the FFM version. Honestly, it was GREAT at the time, but the experience really left our relationship in an awkward place. She'd ask, "Why don't you react that way when I go down on you?" Which led to my angry reply, "Because it didn't feel like someone was trying to strip paint off a barn." She let the other girl do some anal play with a dildo (and obviously enjoyed it) when I had been denied any kind of backdoor fun at all. So, after a while we both decided to exclude others from our lovemaking and focus on each other. However, one other time we went on vacation with another couple and throughly enjoyed making love in the same room. Now THAT was an experience we'd like to repeat.