How to get Sims to stop cheating/flirting with other Sims

I just got this same problem last night. I had to stop my sims from randomly flirting with other sims and I walked away from my console and suddenly one of my sims had a love bar with someone else. I tried to marry the two sims and on their wedding day the bride kissed her best friend In front of the groom. Plz tell me this is getting fixed it’s so frustrating.