My brother needs an aspirin so I'm going to act like I lost mine.
Why don't you want to give him your aspirin?
I have a headache from practicing with the band because I play so badly, so I need it.
It is not good to lie to your brother, you could just tell him the truth and that you need it. Otherwise he will be upset that you lied to him and he won't be truthful to you either.
Dude, I don't want anyone to know that I suck at music.
That is not what I am talking about. I am saying that you should just be honest with your brother about the asprin. It is not okay to lie like that, it seems petty.