Sims excessively flirt with others

This just started affecting my game in the last month. I don't have the NAP in place, but all adult sims will autonomously flirt or blow kisses, then they end up with negative conversations and moodlets. It's bad enough that I only let them talk to plants for social at this point. I also do not use mods. 

Yeah I had a mod (Conversation Tweak) that reined in random flirting, so can't say when this started, exactly, because the mod was masking it. Though even with the mod i had an engaged Loyal sim and a married Good sim autonomously cheat with each other, (It's Layne Coffin, after the evil reveal, cheating with Miko Ojo, and  Miko's husband is Johnny Zest, so you know their traits)  but it seemed to be a one off, so i didn't realize it might have been this problem leaking through.  But I removed that mod, in order to try a new one, and the flirting was craaaaaaaazy. thought it might be the new mod, so tried things with no mods. and everyone was EXTREMELY flirty, it wasn't just my sims, everywhere i went, everyone was all over each other in the background, even if they had traits like Loyal or Unflirty that should have prevented it. so it's something in the base game, apparently...

there was one exception to the flirting. In the Layne/Miko/Johnny triangle, Johnny had unlocked 'Idealist' and 'romantic' as self discovery traits, and he was the sole sim that was not flirting, except with his wife, despite the Romantic trait, and would refuse advances from others. So Idealist may actually be keeping him in check, at least I assume it was idealist doing it, it's the only trait he has that makes sense to do that.

*edit - Went looking through my screenshots, and looks like the autonomous kiss/flirtation  that started the love triangle was on August 20th, so I think that was probably not related to the new issue people are reporting, and i can't discount a mod causing it in this case. it was just... 'one of those things'  (and i now don't feel so bad about having them divorce after it continued, again autonomously. Shame, they were cute.) but the excessive random flirting even unmodded  was just a few days ago that I was noticing it. It is still weird tho. Like, Layne may be evil, but he is Loyal, and you can see he's tense about it. But he still did this twice in a row, autonomously, and before that Miko flirted with him (right in front of Johnny, too). I'm not even controlling the household!

Since the September 18th update, people are constantly flirting with my sim who is in a committed relationship in front of his partner. This is regardless of their mood. At least once per play session, I have to cheat away the negative moodlets and sentiments that wouldn't have occurred if the flirting remained the way it was before the September 18th update.

I don't have Lovestruck or Eco Lifestyle, so it isn't the Attraction System or the Free Love NAP. 

You got my vote since I'm having the same issue as this will all mentions.

Likes, being in a relationship etc. This is destroying my npcs stories right now so. Right now since this was even in my test clean unmodded save since I had Eric Lewis flirt with some random stranger during the test even though he's married a while ago. I'm using MC Command Centre in my modded to just turn off auto flirting all together. But Just so you know I had this happen in my clean unmodded save while I was testing other bugs when the patches came out. I'm glad this was already reported :)

This has been happening so much to my family, I do find the romantic trait made it worse, if that helps anyone. My one sim had the loyal and romantic traits, he was at graduation (it worked for once) and he flirted with someone else, it ended in a full on fist fight and him being so upset he changed from romantic to unflirty.

But MUCH worse was my sim's parent, who is Morgyn Embers, would not stop flirting with their daughter, they had a romance bar and everything. Now, Morgyn wasn't her biological parent (due to them being sterile) but she was their care dependent as soon as she was born, and she had a sentiment about how they were a relaxed parent. Morgyn had been an excellent parent until this point, this was all in the last 2 updates, including the one yesterday, for me. I play on PC, use only UI cheats and MC Comand Centre, have all expansions but not lovestruck and the only NAP I had on was the being creative one

I tried updating to the latest version on my Mac (vanilla) but this bug was not fixed. Please fix it as soon as possible.

I just started a new save, with no mods or CC.

Sims are flirting with everyone without being in a flirty state or even having a relationship. Neighborhood plans are disabled, and the game has only started for a minute, so there are no voting plans yet.

As you can see in the image, the Sim is flirting with his housemate (who I used to test this). They have almost no relationship since the game is just starting on a new save. He's NOT FLIRTING, and yet, he keeps doing this all the time.

It's annoying, it's ruining all my families, and my Sims can no longer leave the house or interact with anyone.

I reloaded the game for the first time since the glitch occurred and so far from what I’ve seen rn, I haven’t seen it. Is the key to fixing it like reloading the game and praying it works?

not only does she barely know this sim, this sim is literally MARRIED?!? i didn't make her do this

I noticed this too, and I do not think this is related to the Loyal trait.

I think this is another case of the game treating a missing test set reference as having passed the test. This is identical to the "Sabotage interaction falsely available" bug report. A lot of romantic actions had a new autonomy test added looking for two new test set references that I assume will be in Adventure Awaits. 

I was able to hide this issue from my game with an XML tuning mod that created the two missing test sets. I just made them both check to see if both sims were noncommittal. Doesn't really matter what the test is, as long as it can fail and it makes sense for the action.

The problematic code:

<L n="test_autonomous">
. . .
    <L>
      <V t="test_set_reference">
        <T n="test_set_reference">482810</T>
      </V>
      <V t="gender_preference">
        <U n="gender_preference">
          <T n="ignore_reciprocal">False</T>
          <L n="subject">
            <E>Actor</E>
          </L>
          <L n="target_sim">
            <E>Listeners</E>
          </L>
        </U>
      </V>
      <V t="test_set_reference">
        <T n="test_set_reference">154175<!--testSet_UnflirtyTraitRomanticSocialsAutonomous--></T>
      </V>
      <V t="test_set_reference">
        <T n="test_set_reference">490981</T>
      </V>
    </L>
. . .
</L>

(The other bug report: https://forums.ea.com/idea/the-sims-4-bug-reports-en/sabotage-interaction-falsely-available/12597201)