I didn't intend to fuck him but everything just kinda fell into place and there was no stopping it.

So my husband and I were at their place for dinner, having a catch up and I accidentally brought up a topic which I shouldn't have and caused an argument between my sister and her husband.

My husband suggested he stay the night with us so they had space to calm down and sleep it off, they both agreed and I apologized to my sister and hugged her .

We headed home and once we got home we had some wine and chated about the evening and all that kinda stuff. After a while I went and made the guest bed and got the room ready. As we said goodnight I went to give him a hug but he grabs my waist and kisses me passionately right in front of my husband. Which to be fair I also kissed him back and went along with it.

The three of us didn't do much sleeping that night. Me kissing him led to an intense 3some with him, me and my husband. They both treated me as I deserved to be treated.

I haven't been able to look my sister in eyes since that night but I don't regret anything.