Can someone explain to me why you would answer the phone if you knew, upon answering it, that you had no intention of speaking to the person and that you answered just to tell them that you can't speak? "Oh Hi. I can't talk; I'm on the other line." Leading me to my second question: Why would you interrupt someone from speaking, put the person on hold, answer call waiting, only to tell the call waiting person you can't talk? Imagine if you did all of this in person, face to face?
So I guess my thought is this: Talk to the person you are talking to. Then talk to the next person when you are talking to that person.