Permanent 'Near Unfriendly' moodlet after autonomous mean Interactions

This buff does not drive autonomy whatsoever. You might have stuck sentiments from when your sims were being meant to each other, which does drive further autonomous mean interactions. The drivers for autonomous mean interactions can be any of the following:

• The conversation is going poorly (Very Awkward, Insufferably Tedious, Offensive, Abhorrent, Disasteful)
• Mood
• Whether the sims have broken up
• If the sims have a negative friendship level
• If the sim is Evil, Mean, or Erratic
• If the sim has a tense Secret Society sprite (From Discover University)
• If the sim has a Bitter or Furious sentiment toward another

If none of the above are the case, then sims will not be autonomously mean to each other. There's a bug in the game where sentiment relationship bits get stuck for far longer than they show in the UI, driving sims to be mean to each other for reasons that aren't immediately obvious.

This buff is simply a proximity buff that appears when around a sim with -10 to -100 friendship, which is the same range that drives autonomous mean interactions.