Help! My sister hates my BF

Tyler

So I have been with my BF for 3 years now. I met him in colleges and we’ve been stuck ever since. Well I have a fraternal twin sister and she hates him. I’m not even sure when it started but I think it got bad after she and her boo broke up. She would tell him she didn’t like him and would only talk to him if she wanted something like if he brought pizza and she wanted a slice or if we were out and he had a bottle she would ask for a shot or two. Well she went to apologize to him about it one day and he basically told her he didn’t like how she treated “these other ni**** out here better than me.” She took it the wrong way and said he disrespected her. But he wasn’t wrong. What he meant by it was that her crap friends that she hangs with that leave her at the club with no ride every time they go out she treats with more care and love than me. Well she went off on me and was saying how disrespectful he was. I went to my parents and they spoke to him too and they agree that she took it the wrong way but what he said wasn’t wrong. Almost a year later she’s still stuck on it and every time I mention his name she goes on about how disrespectful he is. She doesn’t talk to me anymore and she claims he is coming between us but he’s not. She is the one that is carrying the situation. Now he thinks it is affecting our relationship and I’m afraid he’s gonna leave me. What do I do?!?! We’re supposed to have a family meeting on Sunday with my BF included to try to squash the situation. Our mutual best friend who has been around since the 3rd grade/ we are 23 now said that my sister says she just wants our parents to say he was wrong and it wasn’t his place to say that because he’s not apart of the family. Do I think he could have worded it different ? Yes but he’s not wrong, and he’s been around for 3 years so I think he is kind of part of the family. Please help me it’s driving me insane!!!