I've seen this, too. Also Sims who have known my Sims' pets for a long time will walk over to where they're just chilling on the cat tree or napping on a dog bed minding their own business and start yelling and shaking their finger. I HATE THIS. I usually make them leave.
(Sometimes, for laughs, I use Twisted Mexi's AllCheats to make pets selectable and have the pet use the "Send Home" interaction.)
@siirysiir Pets weren't intended to be playable so the options are limited. You can tell the cat where their food dish or litter box is and have them play with toys, etc. I'm embarrassed to say that my most commonly used use is to see their needs, but I have some older cats who lose track of their food dishes a lot. Some of the options that weren't intended for pets give you nightmare animations (Friendly Introduction, lol, don't use that). BUT, "Send Home" is available to pets if you have them selectable.
I've only used the AllCheats mod, which gives you a bunch of command-line stuff (some of which is potentially dangerous, lol), including the command to make pets selectable. I haven't tried the official Playable Pets mod, but might.
@siirysiir If you have AllCheats, you're all set to use pets.toggle_selectable_pets in the cheat console. If you've done it right, you'll get a "Pets are selectable!" message. (If you turn it off by running the same command, you get a message like "Pets are no longer selectable! Good luck!")
You can then select them with the spacebar (the hotkey to toggle between Sims) or by clicking until the next time you go into CAS or change households/reload the lot. I think the main thing the dedicated Playable Pets mod (it's by Andrew and Orange Mittens) does is leave that toggled on permanently.
