Opposite sex Sims flirting with same sex Sims

This actually happened on vacation in Granite Falls. To my knowledge there is no NAP there. Even so there was no freelove NAP going on at the home residence either. I turned off NAPs because of that one and the foodies unite. So the only things that get enacted are what I choose and vote on. 

The other times this has happened I did not catch it so I am not really sure what happened, though I seem to remember something about enchanting introduction happening with a different sim before I could stop it. This one is one of those hard to gather data things. Maybe I should have waited until I had more than one instance before reporting. I just wasn't sure if it is going to become a problem since they seem to come and go on a whim in my game. I will be more diligent trying to catch these.

 I have noticed something else that might be part of it, or a separate issue entirely. The game sets most, if not all sims to swing both ways and I change them in CAS to only be interested in the opposite gender. When I have them out and about I frequently notice the green hearts with plusses happening when they're having conversations with same sex sims. I'm sure this has not always went on because it's been bugging me, but it hasn't done anything like create a romance bar, so I have been ignoring it while trying to figure out what is going on.