You can have a bot reply with "ah! Give me a second" or something along those lines while you're away. There's no need for a sophisticated solution, as people already know you're a person and are thus not very likely to suspect a bot (assuming you don't tell anyone that is).
I used to do this while botting MUDs. Immortals (administrators) would check up on you occasionally, so first my script would send a "mis-channel" communication to make it look like I was actively talking to someone else, then a quick "Ack, sorry" followed by a pause and a "one second". All while simultaneously sending me an SMS so I can take over the communication stream in person.
