Not Invited To His Son's Birthday Party

My boyfriends son is turning 8 this weekend. Me and him have been together a year and a half and I've met his son. She's having the party at her house, but she told him I can't go because she doesn't like me. That hurt a lot. A part of me wants him to say well I'm not going then, but I cant ask him not go to his son's birthday. I'm honestly 100% sure she still loves him. What would you guys do?

Edit! I'm sorry. I accidentally put month when it was year