i did that once,years ago.
was sitting in with my mates and i completely forgot for a second that my mum was expecting a call regarding my wee sisters communiion....
phone rang and i picked it up and said "Funky stud dating agency,would you like a funky stud?"
"hello,its SIster Theresa is this Suzanne's number?"
i hung the phone up and got my mate to answer it when it rang again,like nothing had happened