Can't romance in incestuous relationship

[wolf1000]

Hey, please help. I am beginning to feel quite frustrated because I have all the right things unlocked (they both have the incestuous traits) and they can have sex, but they can't romance. These are the options that pop up. With other sims, the normal options do pop up. 

I've tried even using cheats to increase their romance to see if that was the problem. I've changed their attractiveness to match each other to see if that will help. I've unlocked incestuous trait for all sims to see if that will work. But nothing seems to give results, hence why I have come here.

Would love to get this resolved