Now you never get jealous because you know chara would never cheat on you but when she see's a girl being a bit too handsy and or flirty she gets really mad,like this one time when a girl name susie was flirting with TJ 

Susie:your so cute

Tj:t-thanks susie b-but

While he was trying to explain why he was not interested she would look behind him and saw Chara giving her a deadly stare

After seeing that she and any other girl never tried to flirt with you again