There is the player trait that is already in the game, get it either by completing the aspirational goal, or enter the cheat to just give it to your sim. That would stop all jealously, and certain maxed skills, along with the reward that allows your sim to put another sim into a romantic mood. I had this one sim who had all of it, and it didn't take any mods for her to become the town's biggest woohoo-maniac. I no longer have her because if I wasn't actually playing her, and she was running loose in the game I can't even tell you the number of couples she wrecked the relationship of, but it was alot.
