I've had many requests from couples (I assume it is a couple, but it's probably a guy)if I was interested in joining them. While this sounds like fun, it has it's downsides.
Once I was at friend's house for a party and felt I was too d***k to drive home. I decided to stay over. The wife (who was a friend of mine for years and I have got it on with once) was being frisky and flirting with me. I, of course in my d***ken state, played along. Long story short, we ended up in bed and her husband joined us. I thought it was a good time and didn't think much of it.
Apparently, my friend thought otherwise. As time went on she felt he "paid too much attention" to me. It ruined our friendship and almost destroyed their marriage. I don't blame her. If I watched another woman suck my husband's cock, I guess I would be jealous too.
The moral of the story is be careful of what you wish for.