Cheat/Mod Question?

Hey, so I'm trying to play a story in my game and in my story I have a sim who has a one-sided crush on another sim. But, the feelings are not mutual.
Unfortunately, I do not know of any way for them to have separate feelings for each other. If one flirts and gets rejected, the romantic bar decreases on both ends. I can't find a way to have a "crush"

Is there a cheat/mod that allows this to happen? I have MCCommand Center and even that doesn't seem to have what I'm looking for