One of the most erotic experiences in my life happened when some friends were staying over at our place a few years ago. We’d had a great evening and to cut to the chase, we ended up deciding to swap partners. My wife went in to the spare room with Mark and I stayed in our bed with Claire. I had sex with Claire and as we lay recovering, I could hear my wife and Mark fucking in the other bedroom. It was obvious they were trying to be relatively quiet but I could clearly hear the rhythmic movement of the mattress, their heavy breathing and the occasional stifled gasp from my wife. I was shaking with emotions as I clearly heard her orgasm. This was followed shortly after by the distinctive slapping sound as he pounded her harder and faster as they became unable to control their own sounds. I could hear Mark groaning and my wife trying her best to suppress her own sounds. He banged her furiously for a short time bringing my wife to her second orgasm and presumably pumping his load deep inside her. Around ten minutes later, I heard my wife go in to the bathroom. At this time Claire went back to Mark. My wife returned to our room a few minutes later wearing a pair of white cotton knickers. This was proof to me that he’d fucked her without a condom. She slipped in to bed beside me and we said nothing. Although it was less than an hour since I’d had sex with Claire I was so aroused by listening to the action in the other room, I was rock hard and ready to go again. My heart still pounding, I pushed her knickers off and made love to her myself off-loading my cum into her along with Marks. An experience I’ll never forget.