Sadly, I fall into this with my husband all the time! He will argue and argue just for the sake of making conversation! It drives me nuts. I see DS starting to pick up on it.
I think you'll find yourself having more patience if you talk less and when you do talk, get extra silly about it. Something like a very very overexaggerated silly voice "Oh yes, of course, you meant cold not chilly, I can see how cold might have confused you since you were talking about being chilly!"
When you need something done a simple "You can talk to me again when you have put your clothes away" then walk away. Don't let him engage you. I'd stick a sticky note on the mirror that says "Wash with soap or don't come out." If he comes out, don't talk, just walk into the bathroom, point and walk out. Less talk, more action!
Don't keep repeating yourself, you're going to go nuts! I have found that many years teaching middle school has made this part of parenting easier. There is nothing a 7th or 8th grader won't argue about!
