TS4 Lovestruck Positive Thoughts Discussion

From what I’ve seen, loyal trait doesn’t stop them from cheating. They just get a sad moodlet if they do betray their partner. 
They also get a happy moodlet from following the code, if they don’t cheat. My sims have gotten that trait through those self discovery moments. None of my couples have autonomously flirted with anyone else with LS though, it was something I was worried about but now it’s not really a thought.