He’s a rock, but you’re no hard place.
He thinks he scored points with his “kicking me out because I won’t clean a bathroom” calculation — because you responded by quibbling over the definitions of “kicking out” versus confronting the laugher at the heart of his argument. That validated his whine as legitimate.
The response he deserved to hear instead was this: “When you don’t clean a bathroom, your brother, father and I do it for you. So, yes, you’re being kicked out for not valuing our time and comfort as much as you do your own — your brother’s in particular. But call it what you will. You have X weeks to turn this around.” Don’t remind, nag, warn, badger or argue with him again. If he doesn’t start doing his share on his own, then follow through with the consequence by notifying him of it early next spring.
In the meantime, let him know that any belongings he deposits in common spaces stay right where they fall if you can stand it, or, if you can’t, get moved to a box in the garage. As is. When his last pair of socks ends up in there, he can fish them out — and wash them — himself.
This is as deeply as I recommend engaging. In fact, please think of these steps as calculated disengagement. You are his parents and you clearly have one more important lesson to teach (his future cohabitants beg you), but he’s also the product of many good lessons well-learned: He’s working hard, he’s saving, he’s not self-destructing at a crossroads where too many do. To hold the line on abandoned socks is necessary, but to declare war over them? That risks squandering an apparent 20-year run of good will.
Thinking of letting go
For the love of psychic housecleaning, pull the plug. No explanation.
In the time you won’t be using anymore to watch her status updates, or date people you only measure against her, or strategize the rekindling of your relationship, consider doing this: Be your own first choice.
If you’re not sure what that means, then use the time to figure out what it means for you. Better things come when you do.