Being married to an identical twin has certainly been entertaining over the years.
My wife (Deb) and her sister(Sarah) are so much alike even I after forty years of marriage have a problem telling one from the other most of the time.
Deb and I have throughout our dating period and all of our marriage have had no problem sharing ourselves with others on occasions. It keeps things spicy in our lives and makes our sexcapades even more thrilling telling eachother about their experience much less the times we have threesomes or moresomes together. Doesn't happen as much now as in the past but each time is special.
Now Sarah has always been a stick in the mud. She lost her husband in a car accident after about ten years of marriage,some five years ago and is just now coming around to enjoy some of the pleasurable assets of live, I actually never thought it would happen,myself. I still bet I could count on one hand the number of guys she has allowed to fuck her and unfortunately I am not on that list.
Even though I certainly would love to get on that list ,Deb from the get go put Sarah on a hands off approach to me. Honestly I don't think Sarah even entertained the fact of letting me run wild with her body,at least for those dull married years she experienced. But now I see things loosening up and she at times , seems to be losing some of her inhibitions,thankfully. Who knows maybe one day.....
I remember the day Deb came home after telling Sarah of our marriage arrangement
Deb said after Sarah picked her jaw off the floor they talked all afternoon about fucking others..Sarah couldn't believe it at first,then Deb told her about fucking Mike(her first boyfriend who actually got her cherry and who just happens to possess the damn fattest cock I have ever seen before) and how they still meet up from time to time and get it on ..She said Sarah just couldn't believe it. So in her little wicked mind she was gonna show Sarah she wasn't bsing and invited both of them to our lake house as guests.
This was about 2-3 years ago now I guess and Deb,Sarah and myself had been out riding in our pontoon boat for several hours and it was hot as hell. We came in and there was a call from Mike who said he was lost and couldn't find oir place so I called him back and went to meet her and lead him back.Deb and Sarah had already hit the wine and were going to chill . During our boat ride I had coerced the girls to ride topless some and they had gotten a slight burn,so they were going to take showers and lotion up .
I brought Mike in and barely saw someone, I presumed Sarah, going into a spare bedroom as we walked in,then Mike asked where the girls?
I said I think I just saw Sarah heading that way and I hear the shower running so I guess Deb is in it. He grinned and said good,as he grabbed his crotch and said I have something I have been saving I want to give her if you don't mind been saving up..I grinned and said go ahead ,I have already had my turn at her today. He made a beeline to our bedroom then presumably to the bathroom...
Not three minutes later I heard this sort of whoop...aaahhhhh scream coming from the bathroom , a few minutes later Mike comes into the kitchen area where Deb had come when she heard the scream too. His face was about ten shades red and he had a look on his face that made both Deb and I bust into laughing.
As it turned out that was Sarah in the shower,not Deb and Mike in his horny state had tugged on his fat cock until it was hard then walked into out big tiled shower. Poor Sarah was bending over washing her feet and definitely was not expecting a huge cock to come poking at her while she washed,but that was what she got.
Mike explained this throughout Deb and my laughter ..that when he saw Sarah she had her back turned towards him and her ass up in the air ,obliviant to what was coming next. Mike said I slid up behind her and placed my cockhead right on her pussy lips and gave it a small forward shove. He said then all at once she screamed .jumped forward and hit her head on the tile wall and ended up on her ass on the shower floor right in front of me still holding onto my cock with my mouth wide open.
He said I knew right then it wasn't Deb I was poking into and started immediately trying to apologize but it seemed like she was much more intent on getting me out of that shower then hearing any apologies at that moment..
I was laughing so hard I almost couldn't catch my breath
Deb went into our bedroom and in a few minutes came out with Sarah with a face almost as red as Mike's.
That weekend was a first in many ways for Sarah, She wouldn't relent to Mike's fat cock but in later get togethers I certainly believe she gave it a try,although neither one of them will spill the beans to me.

Just one of the many,many crazy fun times we have had and hope to continue doing.