Maid of Honor and Best Man situation

by Mississippi Burning
(The Delta)

My wife's best friend is getting married in the next year and she has been selected as her Maid of Honor. They have known each other for years and are like sisters.

At one point in our relationship, prior to our marriage, my then girlfriend and I had decided to break things off, but we still remained in touch. She moved to California and I remained in Mississippi. She admitted to having a one-night stand with the guy who is to be the Best Man in this wedding. Again, we were not together. But when we did finally get together and decided to marry, she revealed her past and his name came up, but she urged me that he was someone that she would probably never come in contact with again.

Well, I guess that's not the case since they are going to be in the same wedding. How should this be handled...