Why would you ever want to tell anyone you are botting? Just bot, but make sure you KNOW YOUR CLASS/SPEC so you don't look like a clown when they ask questions. Botting is frowned upon, people get jealous that you can just turn a bot on and jerk it and top the meters, while they are trying their best to top the meters while paying attention to mechanics. If your friends say you're pulling insane numbers, tell them its a AOE fight and you're a lock, its one of the top DPS classes. Just pug and get gear, find a new guild to raid with and bot, they don't know you and won't question your DPS.
Edit: On a side note, you tell anyone you bot, even a close friend, you are compromising your account. Fall outs do happen, and if your friend gets mad at you for what ever reason and decides to report you, GG. If you bot, just keep it to yourself, no one needs to know how you play the game, they just need to know you play it.