Constantly fighting

We use a kitchen aide cheese grater and my husband thinks it needs to be washed as soon as it’s done being used. Doesn’t want it sitting in water to soak it needs to be done the second your done grating. This has become a HUGE argument in our house and I’m fucking tired of it. Wtf is the big deal with the fucking cheese grater? I don’t understand. Literally yesterday I set it in the sink in a Tupperware of water that I knew was from my leftovers from lunch I told him don’t even say anything I’m running to grab a new sponge and I’ll be back to wash it. What does he do? He opens his mouth and says something about me putting it in the water….this caused a huge fight. Yelling at each other in front of my kids which a HATE. I even slept on the couch. I’m so fucking done. It’s a fucking cheese grater who tf cares? His claim was HE didn’t know what the water was and for all he knew it could be from raw chicken with some bacteria in it. The issue was I was going to wash it, I was going to take care of it so why does it matter what you did or didn’t know if I was taking care of it? For fucks sake I’m so done. Can anyone enlighten me why this might be such a fucking big deal?!