Apple Id purchases history please hell?

[A]

I used my brothers apple id to download apps. I don't want him to know about. Like yahoo messenger, ebuddy etc. they don't know I had yahoo. Can I say I downloaded by mistake? Further, say he downloads twitter too will he be able to see my account I am always signed in. He allowed a few of us to use his id will he specifically know it was me? I logged into his account to see if I can delete you can only hide, will he know? Will apple ever allow delets ?
Thanks