Aww, I'm sorry to hear they won't be attending this important event for you. My sister didn't go to my 8th grade graduation and I went to hers, but I wasn't really mad about it. Just think of the people who don't have anyone going...

But you're right to be mad, they shouldn't have annoyed you about going your brother's graduation if he didn't care, and he shouldn't be such a hypocrite about it.