Address your employee the same way you'd address your boss. Unless you're still a two-finger typist, "I'm not clear why this hasn't been taken care of. Can you please send me a status report? Thanks," is not an onerous message to compose.

Track your spending. If you have a laptop, use a spreadsheet and set up some simple formulas to automatically add up your purchases. Or simply write it all down in your journal.

Reply to the client, and then forward the whole exchange to your colleague. Just bear in mind that said recipient is going to read everything in the conversation up until that point. Have some tact and stop yourself from playing fascist dictator when replying.

If you're the one providing the info, don't just paste it into the body of an e-mail and hit send without salutations or a sign-off. That just makes it sound like you're pissed off to have to help.