My girlfriend Jean, has 2 children from a previous marriage. Her and her ex-husband Matt had a rare mutual breakup, and were still cordial. He had to travel for work to South Carolina often, and was offered a position to move there. She couldn't move away due to having to care for her elderly parent. He actually lived fully in South Carolina for 2 years before they agreed to end their marriage. He eventually married another girl, Susan from down there.
She had split up with Matt more than 3 years prior to us getting together.
Matt's parents still lives in the area, so he would make trips up to visit the kids, and his parents about once a month or so, sometimes bringing Susan. Also, she and the kids would go down for a week vacation in the summer to visit.
At the beginning, I didn't want things to be awkward, so I would not be around when Matt was there to visit or she travelled down.
It wasn't until a few months that I found out, Matt (and sometimes Susan) would actually stay at Jean's house for the visits. I had assumed they stayed with Matt's parents or at a hotel. When I kinda asked about it, she explained that he had always stayed there since their break up. He sleeps in her son's room (when Susan comes) or on the couch. It's just how its always been.
I get that, and understand how it is just a common thing of convenience now for their situation. It was like that way before me.
As time progressed, I would come around and also stay the night some at her house during Matt's visits. Never was an awkward moment between us.
Our sex life was great, Jean was really playful. During one of our pillow talks, I asked her about any wild past experiences. She said she had had a 3-some before. When I asked further, she said it was with Matt and Susan during her visit to their South Carolina house. She said it started a year before dating me.
I was shocked but interested... I asked "started"? That means you did it more. And she said yes, several times. She asked if I was upset, and I said no. I told her I was kinda turned on by that and want to know more, how did it happen, etc.
She explained that all 3 of them was in their hot tub. Susan jokingly mentioned that Matt had "fucked both of these pussies before". Matt jokingly replied. "Oh, I'm sure Jean would still let me fuck her". Susan challenged him, and told Jean that she wanted to watch Matt fuck her. After, some reassurances, Matt fucked her on the side of the hot tub with Susan beside her. She said they had her stay with them in their bed that night and they all played several times over the week.
I told her that was awesome and I was really tore up. She explained it was only sex, nothing more. Just for casual fun and nothing more. I told her I understood and that it kinda turns me on. I asked does it still happen, and said yes. "Even since we have been together"... and she said yes. "And what about just with Matt alone", and again she said yes. I asked how often, and she said nearly everytime he visits.