In this movie Doris Day is sharing a party line with Rock Hudson. Every time she tries to make a call Rock is on the line talking to one of his many girlfriends. While Tony Randall is visiting Rock in his apartment, he uses the phone to call Doris Day. When he dials the number he gets a busy signal.. How is this possible. He's using Rock's phone, he should be hearing Doris' conversation as she does when Rock's talking to someone.