My sister rejected a handsome and successful guy so I'm gonna call her a dumbass.
Why be so mean to her? Do you have other problems with your sister?
I think she's just a dumbass. It's just what she deserves.
You should not disrespect your sister by calling her names. Instead, you should stay out of her love life and respect the choices she makes for herself regarding who she wants to be with.
This is a family thing so stay out of it.
I understand that it's a family thing and you don't agree with your sister's choice, but it's her life, and she can live it as she sees fit. Calling anyone a dumbass, especially a family member, will just upset them and will make them angry with you. Instead, you should respect her decision and stay out of her affairs.