The code for fated mate is set to give you a 50% chance EVERY time you run a flirt interaction with a werewolf. Lumpinou has a mod that changes it to once per SIM and reduces the chance to 15%. I imagine maxis made it like this so that it would be easier for a player to get a specific sim they wanted to BE your fated mate...and did not take into consideration the opposite effect on people who pair their sims up in a different way. How bad is the tense moodlet for flirting with a not fated mate?
Edit: that tense moodlet is pretty brutal, +3, oof. I wonder if when they said we can ignore the fated mate thing, what they really meant was "just bury the tense moodlet with a bunch of other happy moodlets that the game throws at you."