There is a third possibility, which is that you and your wife were "primed" for something like this, at a previous time, without either of you being aware it was happening. Hypnagogue recently brought up the concept of "alert hypnosis" in another forum: a situation where suggestions are planted in people's minds while they are in perfectly normal consciouness. British hypnotist Derren Brown does this to people on a regular basis while being filmed doing it and the results are remarkable:
http://www.channel4.com/entertainment/tv/microsites/M/mindcontrol/video/
His skill lies in part in a thorough knowledge of how to
suggest, rather than directly state, and in recognizing when a person is sufficiently preoccupied that the suggestion will take hold without their conscious knowledge.
I don't think people like Derren Brown go around randomly planting such suggestions in unsuspecting people. I think most such suggestions get planted inadvertently. If you watch the Derren Brown clips and read his explanations of how he does it you'll be able to piece together how this could happen, and see that people like Derren Brown learned it was possible to do such things by observing them happen inadvertently in the first place.