Why do girls get jealous when you compliment other girls?

Anonymous
It always happens
It happened twice today

When I compliment a girl
The girl who overheard the compliment but wasn't complimented gets jealous

Like today I was sitting beside this girl in theater room
I would say my friend but we're only friends in school I don't contact her outside of school

But anyway she's known for having a good size bust
When my digital literacy teacher walked by she noticed me staring at the teachers breast which are bigger than hers and says

"they're probably fake, and she's old. "
Why did she get so mad and jealous

Why are some girls like that
She talks about Boys to me, and around me, a lot,
I really don't care
But once I stare at my teachers bust she gets mad and jealous?
Why do girls get jealous when you compliment other girls?
21 Opinion