Senior year of high school. Standing around after school with a couple of friends making inconsequential conversation. I have the maturity of... well, a high schooler and make a "your mom" joke. Her mother had died a few years earlier. I stood there for half a beat before I realized who I made that "joke" to and just walked away. I like to pretend that it never happened.
That 'your mom' bit has happened to me before too. The response I got was 'my mom is dead you fuck!'. Not my best day.
I used to work at a restaurant with sounds_sound and I would ask new servers to ask him how many pushups his dad could do and without skipping a beat, and in a completely believable way he would say "my dad only has one arm." It was hilarious, because it was fake. Yours... not so hilarious.