Girlfriend don't get it

Gf still talks to her ex - sending reels and what not. They dated for a while before me so I understand that them being friends should be okay. BUT as a man, it still annoys me. I know this is my ego, exes can be friend blah blah but ifykyk. Like she knows that it annoys me but still proceeds...if I was talking to another girl I know she'd be jealous so I be respectful and stay in my lane but how come when the tables are turned - the respect ain't there.