Unexpected Unicorn

A little more than a year ago my husband cheated on me. Let me back up, when my husband and I got together, I was cheating with him on my ex fiancé, however I knew he was the one, we both were very aware that we are very open sexually and like to have different partners, so we agreed that if we ever felt a desire that we would just open up the relationship, however I took a long trip out of the country came home and it was clear to me. Something happened while I was gone, so I did a little digging, and was able to determine that he had some people over one of which he had sex with so I confronted him about it and he confessed and told me all about what happened and mentioned she would be up to a threesome. I called the woman the he had sex with and I told her I knew what happened, and my husband says you like girls too and would be down for a threesome she told me yes. She can and met me alone and we had a wonderful time, l eventually rearranged all three of us together. She was also married however, her husband was living in a different country awaiting a green card. Fast forward my husband has now left the country because he was shipped out for work and her husband is now here, so she invited me over for drinks and to watch TV And she looked at me and said hey come here for a minute she walked me to her bedroom where Her husband was at and said she wanted all of us to get to know each other. What are your plans now your husband’s gonna be gone for a year. I said I plan to work a lot she says no I don’t mean those kind of plans what kind of sex do you plan a half as I haven’t figured it out yet she’s like I have a plan for you and she invited me over to the bed with her husband . She started going down on me. Next thing you know I have been an unexpected unicorn in this relationship that I am now asking to be to be faithful to until my husband returns. I enjoyed the experience but this is oh so new to me.