Oh is that what this feature is called. A total stranger interrupted my Sims wedding last week. She just showed up in jeans and started chatting up the bride in her wedding dress. I couldn't make her leave, because it was in the wedding park lot in San Myshuno. And she wandered around chatting up all my guests and eating all the food lol. If she just wore a dress or something it wouldn't have been so bad lol.
I didn't realize that you don't actually become acquainted with them though. That must be why I sometimes can't find a Sim to call if I met them on a lot and I guess they chatted to me and I never introduced myself?
In general, I do like that Sims come up to your Sims though, I just think it needs a little fine-tuning. I wish it could be restricted to Sims who are the same age so child Sims or Teen Sims get in their own little chat circles. Or you should be able to turn the feature off sometimes. I wish you could remove people out of group chats if you don't want them in the chat circle, is this possible?