The unlock requirement for the Motive-ating Special Touch is that a sim experience no negative moodlets for three days. I've tested this in a few save files (including in a fresh save created after uninstalling all mods/CC), and although I've had sims experience no negative moodlets for up to a week, I still haven't been able to get it to unlock.
Things I've tried:
- Double checked that it was no negative moodlets, not just no negative mood state
- Gone over the three day period
- Cheated needs to avoid negative moodlets
- Gone the same duration without cheating needs in case the cheating was the problem
- Fresh save, never modded
- Clean install of game, no mods, fresh save
I've also had a friend who has never used mods test it on her PC, and she, too, can't get it to unlock.
FWIW, I have all DLC installed, and the sims I've tried this with have been able to unlock every other Special Touch.