Swing

I couldn't quite believe what was happening as I looked over and saw my wife's head bobbing up and down as my friend's moans filled the room. Actually, I could believe that part; it was when I looked down to see his conservative, shy, innocent wife doing the same that I struggled to believe it. But that was just the start of this Ski Trip with a difference! When I watched my wife move in to kiss her, I could see the fear in her eyes.
The way she shook, the way she was breathing. She was terrified. But her nipples gave it away; she wasn't terrified of what my wife was about to do. She was terrified she might like it too much!