I read the 'bathroom joke' and just had to chuckle. So much of this happens, or has happened through out the years.
I have teens here and I swear I can sneak in the bathroom and it's just like they have radar and know I am there and will start something even at their age! Or if not home, the phone will ring and it's one of THEM! Never fails.
I sometimes ask my oldest daughter if she has a special camera that she can see if my bathroom door closes or something since she always calls when I go there.