Sims' relationship builds itself

@igazor I'm pretty sure I found the culprit. I trashed my most recent save and reverted to the next-latest one, which was just before I told my sims to move houses. The sim not calling in the move was just standing around waiting. (As noted previously, the relationship gains must have started 45 in-game minutes to 1 hour earlier based on the total relationship value relative to the day before.) Whenever I let him do as he pleased, he wanted to play in the sprinklers—he has the Loves the Outdoors trait—and although I never let him, he did go a few steps in that direction. Combined with my manually adjusting the relationship level (on the other sim), this interrupted the automatic gains every time. On the other hand, if I told him to pace back and forth waiting for the move to happen, the gains continued despite all interventions short of an MC reset. I think he must have tried to play in the sprinklers an hour before I saved, and somehow the group activity gains got stuck. I know that if one sim is playing in the sprinklers, he or she will try to talk with anyone else around, as the other sim was. I also know that in every game where this happened, at least one of the sims involved had the same Loves the Outdoors trait, and they all seem to think that running through the sprinklers is the absolute best activity in the world. Even the ones that have the most expensive TVs, several upgraded computers, trampolines and Sim Gnubb, and all kinds of hobby-related objects to choose from. This is something I will never understand, but they're welcome to their diversions. (Unless they're supposed to be making money. In which case, ::cracks whip:: back to work!) Just kidding. Sort of.

Anyway, thanks for responding and trying to help me figure this out. This problem has bugged me for a long time, and I'm glad you engaged me to try to nail down the cause.