Why more confidence in a single man as a Confessor than in a married man?

The Catholic Answers

Because single men can give undivided attention to their duties, and have more time to study and know the law of God upon which they must base their advice. Then, too, people feel that one who has renounced earthly affections for the love of God has more opportunities of living a disinterested spiritual life, and that his words will be correspondingly more helpful. And last, but not least, a single man is not so likely to share his thoughts and worries with a better-half, or betray a confidence through indiscretion or inadvertence.

Radio Replies Volume 1 by Rev. Dr. Leslie Rumble MSC and Rev. Charles Mortimer Carty