Is anyone able to get their sims reliably joining ongoing interactions through autonomy?
Improvements were mentioned in some of the recent change logs, but no matter how much I fiddle with the autonomy settings it's still an exceedingly rare event.
I haven't tested it with the recent releases, but I had a public release WW after the python upgrade patch, and invaded two poly incestuous siblings relationship (premade sims with high sex skills, and loaded with debauched traits) with a male character that romanced both and became the boyfriend of at the same time, I intentionally achieved autonomous group sex, and my settings are on the average "default" options (I'll give it another look, though, to be sure, I didn't like the high settings as everyone and everything was having sex everytime and I didn't want that, but didn't want the sex to disappear):
I first made the sex crazed siblings romantic with each other, to have the brother pop the sister's cherry (I think it's a NisaK thing, right?), then I had the sister sleep with my male sim, and force clicked the brother into the same room to watch, he first got aroused (soft penis changed to hard), but walked away to take a bath (was tense from turning into a vampire... >.> long story), then I had the brother come back to sleep with the male sim, and the sister was still in the room after her turn, and suddenly she joined in the sex with no prompting on mine or her part (kind of surprising, as I wasn't expecting this feature, I remember there being a ask/message in older releases). This all occurred in the same day (the relationship status and the sex sessions).
Though that was back in the late November release, and I haven't played with them, or any other poly relationship where such could be possible, so I hadn't seen it happen since, and like most said, I'm starting to see a lot of bugginess from monsters/stretch sims on certain interactions (I distinctly remember seeing Anal Nosferatu from Anarcis stretch out the limbs of both partners, that never happened before) and just general weird quirks/glitch from all these new updates (a lot of my sims are choosing to have sex in awkward corners blocked from furniture, or bugging out on windows where the sex interaction errors and restarts indefinitely, until I ww.stop_sex them and the pop into a fenced area), so something could be wrong and needing a fix.
But, if you hadn't yet, and you want, try giving a test run with a few poly/no jealousy traited sims (I believe I gave the siblings cuckolding too, my male sim was loaded with poly and no jealousy traits), and start a sex interaction with one in the same room as the sex, and see if that yields anything? I also used Mccc's relationship cheat to quicken their romance, so if you have to/short on time, you could do that to see if it's a higher relationship thing or something. ¯\_(ツ)_/¯