Feeling bad. Should I say something to my dad? Or let it go?

My dad and I had planned to go to dinner tonight. My brother (27 years old) usually isn't home for dinner so we didn't ask him. Well tonight he is home and just made hot dogs for dinner. My dad accidentally texted my brother and said he'd be at the restaurant at 8. My brother told me "dad accidentally texted me and said for you to meet him at the restaurant at 8." My dad and brother don't really get along and my brother has said he feels like the black sheep of the family. It makes me sad that my dad didn't ask him to come when he realized he texted him by mistake. So now my brother knows. And he asked me if I wanted a hot dog. I should have asked him to go with us when that happened. I feel so guilty and sad.