DEAR ABBY: When my husband and I were dating, he told me that he’d had a consensual sexual relationship with his cousin, “Irma.” He said they were in their early 20s and very immature. They parted ways because they both knew it was wrong, and Irma moved to another state. He told me so one day I wouldn’t be blindsided should we ever be married. Well, we got married, and this cousin has kept her distance until recently. Irma has now started to attend their family events. We live too far away to go, but I dread the day when we ...