Where Will the Fantasy Lead?

My wife and I share a fantasy about sharing her with another man, but like many others we are a bit afraid of where it might lead. Lately - to ease into it - we have decided that we will invite another man into our bedroom while she is tied to the bed and blindfolded. He and I will touch her, pleasure her with our hands and our mouths and tease her with our hardened cocks. Then, he will leave. My wife and I will then have each other. I am so turned on by what I think will be my wife's reaction while being pleasures by two men is a fantasy she has thought about for a very long time.