We had never talked about any sex play with others but wife and I while people watching and drinking would comment on good looking people. Bbq, naked(usually just topless) hot tub with friends happened several times, no sex play at all.
Short version. 1st time. Bbq at our place. Drinking, naked hot tub, into the house, one guy still there. Into the kitchen, still naked, one more shot before he leaves. Dont really know how or why but he did my wife over the back of the couch. Took 3 minutes total. He quickly left. Wife looks at me starts crying and apologizing. She runs off to shower. We go to bed, lay there for at least 2 hours, she cried and apologized over and over, I didn't say much. Next day she asks if I forgive her, I say yes. W end up having great sex. Great sex for a month, never mentioned what we did.
He's the UPS guy at her office. 4 months later. Her and I are good with what happened, I say invite him for bbq again, we talk, no hard feelings, blame it on drunk. Hot tub, drinking, exact same deal, 3 minute fuck over the couch, he splits. Wife cries, apologizes, shower.
We go to bed, 30 in of silence then she fucking the hell out if me.
They talk at work, her and I are kinda into this now. She invites him again, we talk and are cool with everything. This time she sucked his dick, they kissed a little, do the deed, he's gone right after. We go like rabbits.
Just kinda progressed to what we do now.