A: Ted, I can tell that this is not a joke -- and take comfort in the fact that many couples have had plumbing disagreements just like this one.

First, I do agree that your wife needs to understand that you take comfort in having a private bathroom space, and when that personal space is used by someone outside the home it can be very stressful. However, you need to understand that in her mind, she still looks at her parents, sisters, and brothers, as people who do live in her home. I know this because my wife does the same thing with her family. So, when your brother-in-law came over, she wanted to offer him the "best" shower stall in the house since he is family.

Now that we know the mental side of this issue, here's what you can do to solve the physical side of this problem. You stated that your guest shower was "just about as nice" as your shower, and that's the key. This is going to be a little sneaky, but take it from me, it does work!

Very discreetly you need to upgrade your guest shower stall so it's actually "nicer" than your private shower. You can do this fairly easy with a nice massage shower head and a fancy personal shower set up. Also, a pretty etched glass door can be very enticing. Once the upgrade is completed, use the shower stall yourself from time to time and talk about how good you feel every time you use that shower.

Over time, the guest shower will be imprinted in your wife's mind as the "best" shower in your home, and the next time one of her family members needs to use a shower, guess where they're going?

Like I said this has to be done low-key, so take your time and don't rush into this project. And, for all you married guys out there, take note and start fixing up your second showers as well. If not, the guest shower in your home will always be for your guests, not hers.