I have always found my mother in law to be very sexy. She went away on a vacation with one of her girl friends and when I found out that they spent some time on a nude beach it caught my attention. It was my wife, me and another couple there when they brought this up. I asked some questions about it and when they admitted they went fully nude it caught my attention even more as I couldn't believe they would actually do something like that. They even teased that they had taken some pictures but it was not anything that they would let anyone else see. I tried to urge them in giving us a peek but it was my mother in law in particular who made it clear there was no way.

It was a few weeks at my mother in laws place when I was dropping off something for her. Her friend was there and she asked if I could give her a ride home. On the ride with her she brought up their vacation and asked how interested I really was in seeing the pictures. I mentioned they had told us that there was no way anyone would see them. She said there may be a chance if I promised to tell absolutely no one. I had to ask her if she was serious and was told she was. We get to her place and she tells me she had to get me to promise again and do a few other things. I promised and she told me to undress. I told her I couldn't do that as my wife would not approve. She said no one would find out and thought it was only fair if I was to see them she got to see me and even offered to get undressed herself. I began to think about it and she then offered to undress first. She then begins to undress before I gave an answer and was shortly standing naked before me. She was a pretty good looking woman and asked if I wanted to see my mother in law the same way I knew what I had to do. I mentioned my wife would kill me if I did. She told me no one other than us would know because if anyone else did and my mother in law found out she would get killed. She could see I was thinking about it and told me seeing the pictures will let me see in a whole different way and added her body may turn me on but what she was doing may turn me on more. I asked what she was doing and was told I knew what I had to do to find out and said she would give me a quick peek of a picture. She showed me a nude picture of the backside of my mother in law. I made her promise again that no one better find out which she did and I began to undress.

There I was nude with her now and she leads me over to her computer. She brought another chair over and we sat together and began looking at the pictures. I soon began to see individual pictures of each of them. She told me they were taking turns taking pictures of each other. They showed all their parts but were still rather tasteful. She then warns me the pictures I was about to see would change my opinion of them and in particular that of my mother in law. The two them are posing on the beach together in all sorts of poses. The poses now begin to get more explicit as they begin spreading their legs and their pussy lips with closeups. There are them in on all fours showing off their asses and pussies and their fingers pulling open their holes. She was right that my opinion of them might change but I was getting turned on seeing them in this way. It didn't dawn on me at first but as both of them were in the pictures how or who was taking these. I decided to ask and was told to keep looking at the pictures to find out. She then reached over and grabbed my cock. I looked over at her but under the circumstances didn't mind. We then get to a picture with a young guy in swim trunks and I was told he took the pictures. I then get told the pictures will show how my mother in law thanked him. The pictures showed my mother in law pulling his swim trunks down and then starting to give him a blow job. Then we get to pictures with this guy fucking my mother in law. I saw her in positions doing what I never expected in my life to see her do. That was it for the pictures and I asked if she had sex with the guy too. She said she could never go that far on a beach in view of others.She says she could see I liked the pictures and then straddled me on the chair was sitting on. My cock was in her and she began to ride me. I was caught by surprise but after seeing the pictures, her being willing and the promise of no one finding out this I just let it all happen. I was feeling the need masturbate anyways and figured her pussy lips wrapped around my cock felt a lot better than my hand.

I cleaned myself up afterwards and she made me promise before I left that I tell no one I had seen the pictures to which I promised I would tell no one. I was more worried about her telling people of us fucking but knew if she did everyone would find out she showed me the pictures. We each had an incentive not to tell anyone.