I'm going to have to disagree with you, LiaP. The rigid control of contact with a person in another adult's life is a red flag in a relationship, period. I lived with a man who started out objecting to me hanging out with other male friends; then he was jealous of female friends; then he started scrutinizing my cell phone call history; I ended up alone in another state with no friends and no support system. I had a nervous breakdown. The relationship ended with the help of a social worker.

The man I lived with had his first wife cheat on him and had not an ounce of trust left in him for anyone, which is terribly sad. I begged him to get help before I managed to extract myself from the house and his control.

If the letter writer really loves her fiance she could try to work it out with a counselor, but his objection to any reasonable contact with a former friend is a bad sign, and trust is an issue with which her fiance will most likely wrestle for the rest of his life.