Boyfriend snapchats girl who has crush on him

My boyfriend (20) allows this girl to Snapchat him and he answers half the time. She’s had a crush on him for nearly two years. He called her the goblin cause he thinks she’s crazy and not cute but the girl knows we’re together so I don’t see why he even has her on Snapchat. Am I dumb for being annoyed about it? I know he wouldn’t cheat and that he has no interest in her but I feel he’s entertaining her when he does occasionally answer. Trying not to let my hormones take over and think about this rationally cause aunt flow is only a few days away so I’m very emotional. Idc if he texts other girls that are friends but this girl has had a crush on him for two years