Why one of my sims randomly slap another one of my sims?

So two of my sims were on a date downtown, playing cards and flirting and this girl looks at them, twisting face and closing eyes and mouth with her hands like they are doing something wrong and minuses appeared above her head. Then when they were out of the table she goes and slaps my man in the face?? I only saw something like this between teens and parents, when they see parents flirting they do something like this, but all of these sims are adults and had no beef whatsoever before. I’m so confused 🤔