It's bad to keep things a secret from your wife.
Hal has a hobby of knitting that he is embarrassed tell his wife about, and she is out shopping.
Hal wants to do some knitting.
Hal does some knitting and realizes it is silly to keep it a secret, so he shows his wife when she gets home.
Hal does some knitting and quickly hides it when his wife pulls up in the driveway.
Hal's wife is tickled by the harmless nature of Hal's hobby and begins to learn to knit too.
Hal's wife notices he is acting odd and hiding something and becomes suspicious it is something far worse than knitting.