Oh, finally someone speaks up about this, thank you!!
I’ve encountered the same issue. I thought it was my mods (I’m too lazy to test without them).
You know what? I have a Sim who owns a Small Business, and when customers check out, my Sim instantly becomes good friends with them... Like, what??? My Sim never introduced themselves, so why are they suddenly good friends???
At first, I thought it might be the Outgoing + Incredibly Friendly trait. But it turns out it’s caused by the "Beloved Brand" trait from completing the "Esteemed Entrepreneur" Aspiration. I tested it by changing traits with a re-traiting potion and removing the Incredibly Friendly trait, and it still happened. But still, does it make sense to suddenly have a good friend from an ordinary customer?
Recently, I have other Sims. I took them to the Spa, and two of them immediately became good friends with the massage chair/table tenant. FR??? Just ask for a massage (no introduction interaction before) and become good friends??? This clearly doesn’t make sense! Did you add a stranger tenant to your first inner circle after just one meeting?
Additional info: Those Sims are Young Adult age to Young Adult or Adult Customer & Tenant interactions. The same case happen to Child age, while my child Sims gathering with their children popular club. Another child (not a club member) joined a conversation between my Sim with other members and instantly they became good friend.
@.TheSimsTeam, ask me for my save file, and I’ll take the time to test it without mods/CC on my current save to serve your laziness 🙂↕️🙇