On a recent Carribean vacation with my wife, her mother and me the airline had misplaced my luggage. We were at the resort at 11:00am but the airline said they located my luggage but said it wouldn't be there until 8:00pm. All my clothes and items were in there including my swimsuits. I didn't want to lose a day of suntanning and asked my wife how she and her mother would react to me going naked on the clothing optional beach. My wife said under the circumstances she would allow it but didn't know how her mother would react. Her mother had no problem with it and said the 2 of them should join me to make me more comfortable. My wife quickly jumped in to say that it wasn't going to be necessary. Not wanting to dirty the clothes I was wearing, since I would need to wear them for dinner, I got naked in the room and just wrapped a towel around me and made my way to the beach. We picked our spot and off came my towel. My mother-in-law looked over at me and then told my wife she felt bad for me having to do this because of the airlines screw up. She suggested they strip down too but my wife said there was no way she was going to put everything out there for all to see but if she wanted to she was more than welcome. I got the sense my MIL just wanted to get naked to expose herself to me but then thought it was just some perverted sexual thoughts I was having. She took off her swimsuit and I was now looking at the body of a very hot looking older woman. My wife made a comment saying she couldn't believe the 2 of us. Her mother and me tried to get my wife to at least try it but she outright refused. She said she didn't mind us doing it but it was something she wanted to do and said she didn't mind if we did it all week. It ended up that we did go nude all week and unknown to my wife we had quite a few quickies. It made it quite easy for a quick fuck since if she was wet all I had to do was slide it in. I knew she didn't have any sexual diseases and couldn't get pregnant due to her age that we didn't even need condoms. I never thought I would cheat on my wife, and especially not with her mother, but it happened. We came very close to getting caught once when litterally I had pulled out just a few seconds earlier. I had to roll onto my front to hide her mother's juices that coated my cock and her mother had to watch moving much to prevent what I had deposited in her from spilling out.
Once we came back from our vacation we kept up our nudity and my wife was not too concerned since prior to this there was always conflict between us. It was my wife who suggested the 3 of us go on this vacation together so her mother and me would learn to get along better and she was right. Basically, I think her mother was undersexed and now I solved that problem for her. Also, my wife is always tired from work and doesn't want sex too often and this was a way to fill that void and with someone who was much better at it and more willing to try anything.
My wife doesn't know what is going on between me and her mother but is very happy we no longer argue much.