So when she arrived I bundled her into the living room and started in on her from behind, playing with her breasts, undressing her, being a bit more forceful than usual (which I could tell, when I got to her cunt, was working nicely). Then I blindfolded her and teased her some more, spanked her ass, slapped her breasts a bit, used the riding crop on her (not with any great force, it's more a sensory thing). By this stage she was naked, standing up but bent forward, elbows resting on the bench, legs spread, still blindfolded. And she was pretty worked up.
Then, the surprise! There was a knock at the door. I opened the door and there, of course, was my friend Matt. He and I didn't say anything to each other but as I showed him into my place he saw her there, naked, facing away from us, and as Matt took his clothes off I spread her legs to show him her pussy and ass.
I'll leave out the blow-by-blow, as usual. But she kept the blindfold on the whole time. I fucked her, he fucked her. I fucked her ass. We both fucked her. DP. She noticed that he had a big cock (a bit longer than average length, and quite thick) and she even took it in her ass like a trooper. A really superb job, I thought. After we were done she took the blindfold off and I introduced them, we lay around chatting and congratulating ourselves then Matt went back to work and Lisa and I headed out for a well-deserved lunch.