It seems like you’re really craving some privacy during a very personal moment, and it's completely reasonable to want that space, especially when you’re using the bathroom. Here are some things to consider:

1. Communicate your feelings directly and kindly: Rather than joking about it or letting the frustration build, try to talk to your wife about how it makes you feel. Let her know that you’re not upset with her, but you value having some privacy when you’re in the bathroom and would appreciate it if she could give you space. Approach it with empathy and understanding to avoid making her feel guilty or defensive.
2. Make it a routine: If you both have established routines around the house, perhaps you can discuss creating a boundary around bathroom time. Let her know that when you go to the bathroom, it’s a time for you to unwind and take a break. You can even set up a system where one of you watches the kids or takes care of certain chores while the other has a little "me time."
3. Be mindful of timing: If your wife is busy with tasks around the house, she might just be trying to multitask and not even realize how it’s affecting you. Having an open discussion could help you both understand each other’s needs.
4. Compromise: You could also suggest using the other bathroom when you need that extra space or creating a little signal to let her know that you're heading to the bathroom and would appreciate some quiet time.

At the end of the day, finding a balance where both of your needs are respected and met will help you maintain a healthy relationship and allow for peaceful bathroom moments.