My kid won’t grow up.

I’ve got an 18 year old son. He’s out of boot camp with the National guard, going to college. I went to pick him up and we drank 2 beers (legal in my state). On the way home he pisses all over inside my truck. He said he couldn’t hold it he said nothing to me first though) So we get home and he said he will clean it tomorrow. He says he wiped it all down, but there is still dust everywhere (he did nothing). Hire mom says I should let him try to clean it again. I’m tired of driving my truck that smells of pee. I told him he had his chance and I cleaned it. I also told him he is not ever allowed back in my truck unless he’s wearing diapers. His mom says I’m trying to humiliate him. I say I’m trying to teach him personal responsibility and consequences. His mom follows along behind him and takes care of everything for him so he doesn’t get the personal responsibility part. This won’t be forever but I think he will learn the first time he needs a ride to the guard manuevers and has to wear diapers his uniform. Am I wrong?