Gift idea for a spouse: a polygraph test

The place mats at a local diner I frequent have advertisements printed on them: from the sort of motel that advertises mirrored ceilings and in-room neon lighting to criminal defense attorneys.

On a recent visit, I saw a new ad on my place mat, the gist of which was that any average Joe or Janie can now have the power of lie detectors at their disposal.

The ad asks several rhetorical questions, the answers to which might indicate that you could use a good polygraph operator. ''Do you suspect that your spouse or significant other is cheating on you?'' is the gist of one of those questions. There's a conversation I'd like to hear. How do you even bring up the subject of polygraph testing with your spouse?

Let's assume you've had suspicions, asked the loved one about infidelity and heard his or her denial. A dozen roses and a gift certificate for polygraph testing? "C'mon , honey. It'll be a real hoot. We'll laugh about this.'' I don't know. Seems to me that by the time you bring the subject up, the whole trust thing is out the window anyway.

Suppose your significant other wanted to strap you up to the old third-degree machine. Under what circumstances would you say yes?