Sim autonomously broke up with girlfriend.

I'm confused.

Simple, I believe someone at EA compiled the inhouse test autonomy into the release code. That is why the game is so hard to control since the updates for Tiny Living. It may have been an accident but it never should have happened in the first place.
The OP mentioned a couple breaking up by themselves in their game. That is AI and Autonomy going haywire.

Yeah my sim got into an argument with his roomate girlfriend and they broke up. It was a really nice surpsise cause I was considering them getting married but when it happened I decided to kick her out of his life for good and he ended marrying someone else. Random drama that can potentially alter the story is always welcomed.

I had a Sim autonomously divorce my Sim back in July, according to the timestamp on my forum complaint. In that case it was because she "discovered" the Sim she'd been married to and had kids with, and who'd never worn a disguise, was an alien.
Autonomous flirting has caused some drop in a relationship between two of my Sims that I am currently playing with.

I really don't like not having control over everything. (And the autonomous flirting happens even with autonomy off, because it can be initiated by random Sims they interact with.) I hate setting things up the way I want, and having autonomous actions ruin it, especially ones that make no sense.

Huh, I thought that was set to non autonomous...

If they have changed something that would equate a little to more like story progression, I wouldn't be unhappy about it, however, I think a lot would...

I haven't played much since the latest patch so I'll have to keep an out for it.

If this is a new thing, I love it. I remember in Sims 3 I couldn't turn my back on my Sims or they would get into all kinds of trouble, made the game much more interesting.

My romantic superstar would always be out cheating wherever I rotated away from his household. I would run into him in town and he would be flirting right and left. I would go back to his household and lmao over the fights. Crazy times. Sims 4 needs something like this to add spice to the game.

Some like "spice", others prefer control ;)

I admit this has me worried, especially since autonomy off isn't foolproof against sims choosing their own conversation topics (of which woohoo is also one, as is, I'm afraid, Breaking up). I did some quick testing with a married couple and a pair that's going steady. Removed one partner each from the household, marked the new household unplayed and unfavorited, then invited the partners to a visit and went at them with everything the mean category has to offer. No unwanted breakups happened, despite both bars being deep in the red in the end and even some fights having occured. (Exit without savong afterwards, naturally)
So whatever this new feature is, it doesn't seem to be too aggressive. Did anyone have this with a couple where no partner was a Roommate, but a normal townie or another played sim?

@Sindocat do you remember if perhaps your couple got sent to Romance Festival while you were playing another household? I've had a couple's affection drop from full to about 10% today, but I remember having seen them at the festival and getting flirted at by townies. But I'll definitely keep an eye on this.

Sounds like a bug since the argument moodlet wouldn't make sense in this case.