In an unmodded game you can already invite a Pet or a Stray to a party via a phone. I wish there was a way to invite a Pet to raise a relationship with them, without throwing a party every single time! Is there a mod that would allow me to do that?
I know that you can forcefully summon Pets via mods like InSimenator, but as soon as the Pet arrives, it leaves immediately so it's kind of useless...

Have you tried making them temporarily selectable after summoning them?

It actually worked! :D
I kinda assumed it wouldn't so I didn't try, since it doesn't work on passerby Sims... but apparently Pets work in a different way haha

Though, this way stray Pets won't leave on their own like they would at a party, the player would have to make them unselectable again...

Thank you anyway, at least it partially solves the problem ^^

I use it on sims who I teleport for photos. And yeah, you have to make them unselectable afterwards.

Instant Inviter has various options for summoning Sims, which might also work: https://modthesims.info/d/673274/instant-inviter.html