Boyfriend troubles

Okay I need to know if I'm crazy or over reacting. My boyfriend was just grounded for a month so I couldn't talk to him or see him. He was ungrounded August 1. Every time I've called him he's either hung up on me to go talk to his sister or go do something with her or he talks to her most of the phone call while I sit there. He sees and talks to her everyday he doesn't talk or see me everyday especially after being grounded for a month. I totally repsect her and their relationship but it's every time I talk to him and it makes me feel bad. I just feel like a bitch if I say something about it but the last thing I want to do is come between them.