You've been dating him for months now, you're a popular model why he's a singer and rock star, you attended his concert since he wanted to see you while he sings songs about you.

As his concert started a while ago some guy has been flirting with you the whole time, He saw this then immediately got jealous at the sight then sang louder to get both of your attention.

You can tell that he's extremely jealous seeing someone else flirt with you.