As an elder, I told my wife nothing. I told no one anything really, even elders who weren't in my congregation.
When you consider the fact that much of the Borgs arguement against pedophillia revolves around confidentiality, you have to ask yourself at what point is it all garbage anyway. Some confide about marital problems, masturbation, drinking, watching bad entertainment. Those are personal for the most part. But being confided in things where others are hurt and victims could benefit if they knew, you have to wonder what your responsibility is at that point. Of course, if it ever came out that elders could use their discretion in what they let stay in confidence, no one would confess or tell them things anyway, which would solve a lot of problems wouldn't it?