Who is teaching whom? Sounds like your cat is quite the lion tamer! Perhaps what happened is that she learned that your husband is likely to pat her when he exits the shower. It likely became a bit of a ritual for the two of them. Chances are, one day your husband was in a rush, and did not pat her—she might have responded by swatting, meowing or some behavior that then resulted in your husband paying attention to her. It sounds like this has now progressed.
You both need to decide if this behavior is something you can live with, or something you need to change. We think it is cute! If you want to change it, your husband will need to change his behavior. We suggest he towel off in the shower and then immediately leave the bathroom. Good luck!