Sims using random sinks

Happens to me too!! Had to delete my basement gym attached bathroom, they kept going all the way down there to wash hands. I keep yelling, "Why is that sink any better than the one in your bathroom!" (same sink just differ color btw) Arggghhh.. LOL

I was just coming here to post this! I have my family moved into one of the houses in the new Growing Together neighborhood and they ALWAYS go to the kitchen or a different bathroom to wash their hands. It's made for some very embarrassing situations when I have multiple sims using multiple bathrooms at once, like in the morning when they are getting ready for work/school. If I don't keep a close eye on them, they will walk in on each other to wash their hands, since they always play "Musical Sinks" for hand washing. This has really just started since I installed Growing Together and I am not sure if it would happen in a different house, as this is the only save I have played since the expansion launched.

I use Scumbumbo's Don't Wash Dishes Where You Angry Poop mod.
https://scumbumbomods.com/dont-wash-dishes-where-you-angry-poop

There also is a mod to make your sims use the nearest sink to wash there hands after using the toilet, rather than choosing one randomly. Think it doesn't 100% guarantee it, but should still help. It's called "Improved Object Choosing", if i don't misremember.

It might be LittleMsSam's "Improved Auto Object Choosing" from her Random Small Mods (RSM) list.
This mod has changed my LIFE, especially when playing in a multi-story house where sims can spend 2-3 hours traipsing up and down the stairs to use the toilet on the first floor, wash their hands on the third, and then go back down to the first floor to take the shower that was queued up next!
I spend a lot less time yelling at my sims now!

I will have to try that mod. I am driven to insanity by my sims at the moment who seems to be working with the algoritm that "any sink far away is good for me." They're more or less playing musical chairs with the sinks! And that is not mentioning the dishwasher which they will not under any circumstances use, not even when the dishes are right on top of it. Nor will they use the sink in the kitchen, but instead they want the freestanding sink in the bathroom. When I locked the downstairs bathroom they decided to take the dishes to the attic instead, passing no less than six sinks on the way.