Dear Roommate,
You have owed me your half of the electric bill for over a month now and it is piling up with the last elec. bill you owe. You act like you don't have to owe me for some reason but guess what...YOU DO! So stop bitchin and stop having your bitchy, trashy, bad-mouthed little sister defend you and fight your battles for you.
Thanks, the roommate you've been taking advantage of....