Is it worth the effort to follow your husand one day to find out where his mistress lives?

No, it's not worth the effort to follow your husband to his mistress' home. It serves no purpose. Here's the scenerio: You follow him, you knock on her door, she answers it and there you are face-to-face with her. 9 chances out of 10 your husband will be furious you are there. Sure doesn't make sense (happened to me) but they are angry they got caught! It results in you fleeing in tears, or a confrontation that gives neither you or your husband any solution to the problem, and you have just wasted your time and broken your heart even more. Although I don't think very highly of women that date married men, it is still the man's fault for allowing it. They can form the word "no" and some have not and for some reason not chosen to do so. I hope you will not put up with this behavior and be sure he does have a mistress. If so, and you would like to leave him, please seek out a detective to get the goods on him so that photos and testimony can be given in court if you so chose to get a divorce (and especially if there are children involved and you want partial custody of them.) Why would you want to know where the mistress lives? All your setting yourself up for is more heart break. Seeing her isn't going to help anything, especially if "you" think she looks better then you. Don't do it. The better route to go would be to privately confront him in your home. The trust is gone. When the trust is gone so is respect. There is no marriage. Unless you are financially dependent on your husband, you should immediately file for divorce. If you are dependent on your husband, make a plan and get educated, real quick.