Don't scare your wife when she is in the shower.
I am a jokester. It runs in my family and it runs in my wife's family so you would think she would be used to it. And in all fairness she has been very good about my jokes and pranks at her expense, mainly because I do them in the privacy of our home or when we are with families.
My latest jokes have all centered around the shower. We have a statue in the bathroom which has peeked over the top of the shower curtain much to her surprise. I have run hot water in the sink in the kitchen to make the shower cold, and she has been very good about these.
What she did not handle well was my reenactment of psycho. I snuck in and threw open the shower and she freaked out. She did not know if she had stepped on the curtain and ripped it, or if the shower curtain was falling, and seeing me suddenly appear pushed her just a little too far.
So after a heartfelt apology, she actually started laughing and was ok with it. I kissed her and closed the curtain so she could finish her shower. Of course before I left, I discretely turned the water in the shower to cold...