Maybe it has to do with my own marriage. If something is troubling me, it will affect my relationship with my wife. I have discovered over the years that keeping my troubles from my wife only invites more trouble into our home.
When I said that I would have trouble confessing my sins, I wasn't necessarily talking about me. Thankfully, I am now in a place where my sins are pedestrian enough to put the most eager confessor to sleep. However, if someone were in an ongoing confessor/confessee relationship, I think it would be difficult for a good confessor to compartmentalize his duties and to keep tough cases from his wife.
I understand a priest has taken a sacred vow, but if he has also taken a vow to his wife, I could picture a scenariao where a marriage could intrude upon the seal of the confessional.
Personally, I think that's absurd. No more probable than a celebate priest breaking the seal. Remember, there's been married priests in the Church since the very beginning. I hope that "marriage" doesn't make someone any less trustworthy in confidential matters. That would be a slap against the holy sacrament of marriage. It all boils down to the person and there ability to keep a vow.
Why would Paul say, "[1 Tim 3:2] Therefore, a bishop must be irreproachable, married only once, temperate, self-controlled, decent, hospitable, able to teach..." and so forth if this was not a trustworthy state in life, even for a bishop?