Gimme a Break! (1981)

S3E15 Knock Three Times

Nell undergoes hypnosis to recall the location of Katie's graduation ring, but the doctor neglects to lift the hypnotic state, causing her to spill all the secrets among the girls whenever she hears three knocks. As the night unfolds, Nell reveals everything without holding back. Ultimately, she announces to everyone her intention to marry James, but confides in him that she can't go through with it just yet—she wants to wait until the kids have grown up.