Dear John, I actually love you and I think you should be appreciated more as an individual instead of as a song writer, you know? Any who, I really don't know how to tell my boyfriend that I really don't like his sister. I don't want to hurt him because he really loves his sister. Some advice would help a lot. Thanks.
Dear ELIZABETHJCARPENTER ,
That is so nice of you! Here, have a cat for your kind words. 🐱
As for telling your boyfriend, perhaps you can try to gently and easily tell him that his sister kind of rubs you wrong. Just don't ask him to choose between you and her because it would drive a wedge in their relationship.
If you really don't want to be around her and you don't want to talk to him about it, you could always avoid her, but then he might notice and want to talk to you about it. Either way, it would be the best to tell the truth.
I don't know how much help this actually was, but I hope things get better for you!