I tried this with my wife we were at a hotel for the weekend I secretly arranged a well hunged guy to hide in the bathroom we started having amazing sex then I turned my wife around for doggy style I started to fuck her from behind while doing so I called the guy from the bathroom without her knowing I acted as my dick slipped out of her pussy and position the other guy to fuck her I stood back and enjoyed it after a while when she realized what was going on she really got in to it best experience ever​