My grandson Brendan calls me periodically and gives telephone performances. They can't really be called conversations except when he asks if I want to sing lead or backup for our duets or when he asks me to choose which story he'll quote or song we'll sing. He's quite a character! I've been trying to teach him how to end a conversation gracefully, but so far it hasn't taken. Sometimes my son sets a limit and will give him a countdown to end the conversation. I'll hear "3 minutes" in the background or whatever. He's now worked this out to ask me if it's time to go yet. If I tell him no, we keep talking. If I say yes, he hangs up immediately. No good-bye, nothing! Just, "Is it time to go?" Me, "Yes." Then "click" and that's it. He cracks me up.
Sam's comment on the previous post referred to that in case you wondered.