While, thank goodness, it was not a try for baby, with autonomy off and a flirty conversation going, a dating pair of SIMs chose the woohoo romantic social without me picking it. I've never had SIMs in a flirty conversation decide by themselves to woohoo before. So it could be, if you had autonomy on, they got into a flirty conversation and decided to try for baby on their own when you were busy with someone else. SIMs do get flirty on their own and if both of them started choosing from the romantic menu in conversation, from my own recent experience it suddenly seems like any choice is open to them.
This definitely has to be a bug because before there was no autonomous woohooing, you had to pick the choice yourself. Plus I know they did it because I was waiting until they were feeling steamy to choose to let them woohoo and they just suddenly wandered off on their own leaving me confused. I was being careful to pick kisses, hugs, you know the normal romantic interactions. I wasn't sure what to make of it so I'm glad someone else reported this.
I clearly had a romantic relationship between the pair and they were in a flirty conversation which made me hesitant to report it. I honestly thought I misclicked, but having someone else report it makes me more confident that I didn't do that and what happened really did happen.
As for triplets, I've had a lot of twins without any fertility help before so you just got REALLY lucky on that. It is possible to have triplets without fertility lot traits or treatments or the fertile trait. It's just a LOT harder and incredibly rare.
Their skin tone being so different is a little odd. I mean you can see the father so you know around what coloration they should have gotten which is usually locked in on one of the parents or somewhere in the middle if one is darker than the other. I've never had a lighter or darker child than my lightest and darkest color in a pairing before. So that may be another bug.
I hope you feel a little better hearing someone at least caught her SIMs in the act of autonomously choosing to woohoo without her making that choice for them. So something is clearly up when it can happen with autonomy turned off even. They are clearly accessing the woohoo choices and in your case the try for baby one which was never the case before.
