As an adult, what is the worst thing you said or did to one of your parents?

As an adult, have you ever gotten so mad at a parent that you told him or her off? Said something mean or nasty to them, told them to shut the fuck up, something along those lines? Or have you done something that many people would consider mean or inappropriate to a parent? Whether or not you regretted it later is another story (you can tell that here if you want to, too).