I'm not going to pick my younger brother up from the airport
Is there a reason why you don't want to help your brother out with this?
Yes because I don't like him and I'm sick of his behavior toward me.
If you are expected to pick up your little brother, you should be there to ensure that he safely gets to his destination. Abandoning your brother when he needs you will cause him and your parents to distrust you.
I hate lies and that's just a stupid excuse.
You should still just go to pick him up. You already said that you would, so you should stick to your end of the deal.