The only time we strayed from our policy, "Couples who play together, stay together" was when we agreed to try to seduce our respective "high school sweethearts" because we hadn't had sex with them then. We had a code name for each "project" and always kept each other up to date on our progress. Our "sweethearts" knew that we were aware of what was going on. My "sweetheart" understood and jumped at the opportunity; Mrs. Alura's, unfortunately, didn't. He thought it was really weird. I still owe her because of this one but she's never sought to collect. If the right opportunity ever presents itself, (I know what those opportunities are.), I'm sure she'll collect.
Oh, yeah! There was also a time when we had a threesome with the male of the couple we were playing with at the time. His wife was out of the country on business and called us from London to suggest it. She said he was really horney. It turned out she was right.
To do anything sexual without your partner's knowledge is cheating in our book.
Mr. Alura