I used to work at a coal lab with a few other guys. It was a nasty, filthy, boring job. A popular way to pass the time was "cutting" on each other. We'd trade insults on each other until someone would eventually tire of it and bow out in defeat. We only had one rule, NO MOTHERS!
Two of the guys were going at it for quite awhile and were running out of verbal digs to throw at each other.
Rick said "Oh yeah, well, you're illiterate!".
To this, Sonny replied, "Oh no, I have a mom and a dad!"
When we finally stopped laughing we had to explain to Sonny the difference between illiterate and illegitimate. LOL