Sims excessively flirt with others

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. 

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!

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. 

Idk if it’s just my game, but lately I’ve noticed mass infidelity and unfaithfulness regarding relationships. I have three married couples, and every single one of them has cheated, some of them have multiple times. Keep in mind, I don’t even have autonomy turned on, they just turn rabid when they’re NPCs, and accept romantic interactions from anyone and everyone.

Two of my sims were romantically involved in the past (not even official), but I decided to make them just be friends. Except they’re not just friends, because they repetitively insist on being romantic, despite both of them being married. I’ve made them break it off at least 6 times, I’ve isolated them, I’ve supervised their interactions, even debated having them not be friends anymore. But I want my Sims to be able to be friends with their past significant others, and not constantly worry about them cheating. Although it seems inevitable.

I’ve had loyal sims cheat, multiple times, more than noncommittal sims. I think loyal sims should automatically reject romantic interactions from anyone except their partner, or only if their partner has open romantic boundaries. 

I’ve rotated through households, and went back to a household, and my sim had romantic relationships with sims that don’t even meet their sexual orientation requirements, when they’re not open to exploring.

i’ve had NPCs autonomously do an enchanting introduction on my married sims, and perform romantic interactions successfully, when they’re strangers, don’t even know each other, and aren’t flirty. 

I feel like sims in the Sims 4 are way too easy, and promiscuous. It takes no effort to get them to cheat, and be unfaithful. And it’s actually a struggle, and a task to have, and maintain monogamy. Don’t get me wrong, causing chaos is fun, infidelity and unfaithfulness can be entertaining for storylines, but when it’s every single sim, and every single relationship, it gets a bit ridiculous. Sometimes I just want a wholesome family and friend group lol.  

Same thing is happening to me my sim got into a relationship they where both day one teens on short lifespan and then I realised his girlfriend was in the third trimester and the baby dad was a young adult. 

I don’t have any special mods that would cause this. 
the only mod I use is Mc command centre.

I've seen this too but with active sims. I haven't thought about what they get up to when they're NPCs. Yikes 

For example, this happily married couple, their relationship and romantic bars are 100% full. Neither have traits that I'd consider promiscuous or cheat-prone.

While I'm playing the household, a visitor turns up. Someone they don't even know yet, and the husband goes in and kisses her out of nowhere. Like, where did that come from? I don't care if he finds her attractive. He shouldn't autonomously try to cheat on his wife (and in front of her) when he's a happily married family-oriented sim.

The worst part? He did it again later with another sim. He just turned into a horny Cassanova. I have to constantly supervise him to stop him from autonomous cheating.

I don't remember seeing behavior like this in the past. Something changed in the recent patches.

For the record, I don't have Lovestruck pack.

I have been dealing with this issue for a while now. Neither of my MARRIED sims have the Flirty or Romantic trait, they are satisfied in their relationship. I even changed their boundaries and orientation AND cleared any NAPs that could be causing it. At first it was just harmless social flirting that was easy to recover from. Now, it has come to PHYSICAL intimate interacions with friends or strangers. THIS CAUSED THE RELATIONSHIP BAR TO GO ALMOST ALL THE WAY DOWN BETWEEN MY MARRIED SIMS. THEY HAVE 4 KIDS TOGETHER. There are so many more annoying bugs and glitches in this dang game. I have been playing Sims for almost 2 DECADES. I'm about to stop playing. I'm sure ALL of us Simmers would love if EA could fix the CURRENT ISSUES instead of pushing more packs, which causes MORE ISSUES ON TOP OF IT.

I'm having the same problem with autonomous flirting when not in a flirty mood and flirting while in a relationship.  This started recently, probably from the 9/18 update.  I don't use mods or cc and I don't have lovestruck.

The romance bug is back again where all of my sims flirt with everyone and its even worse than the last time. It came back after one of the most recent updates. The last time we dealt with this bug I was able to go back and give all my married sims the loyal trait and that helped out until the bug was fixed. Now since the bug is back, that trait no longer help. My married sims are being disloyal to one another and jeopardizing their relationships. The sims who have a particular set preference are still flirting with sims who are set to not be their type. Its just awful and annoying. Also the romance bar goes down entirely too fast. Which was something me and a few simmers been reached out to you about a long time ago after Lovestruck ep. But that still had not gotten fixed. Please, please fix this so I can somewhat start back enjoying my couples again. Also I don't know what's going on with the graphics but the graphics are getting worse now.

This explains why my Sims are doing all these romantic stuff outside their marriages! I hope they get this fixed. I've had to keep their autonomous turned off for this reason!