This may sound harsh, but as soon as you tell 1 person if any more people find it it's only your fault.
My girlfriend knows, didn't really have a choice there to be honest, she's always around here and would have eventually asked why I left the PC on when I went out. She doesn't play WoW (though one of her sisters does) so it's not a big deal.
I have RL friends in game, even in my guild, and I just don't tell them at all. Why do they need to know? Don't bot on characters you're going to play with friends on, don't bot whilst in a guild. Don't ever tell anyone about botting, there's no benefit to it and there are plenty of reasons to keep quiet.