Is a husband visualizing other women naked a sign of unhappiness in his marriage?

I don't think it necessarily means that they are unhappy. I think it is just our nature. Women are more emotional and we don't go to the whole "naked" thing right off. Men are more physical and I think their curiosity gets the best of them so they tend to wonder what they look like naked. They could have the perfect wife and still do that. I think they are unsatisfied at home when they actually start flirting/cheating. Acting out on it is when your marriage is in trouble. This is just my opinion! Good luck!