Smiling eyes: contraction of the orbicularis oculii muscles.
Reminds me of this quote that’s in our employee manual here: ?The key feature differentiating these types of smiles is the presence of so-called ?laugh lines,? the tiny wrinkles that appear at the corners of the eye during smiling,? she says. ?These are produced by the action of a muscle called the orbicularis oculi, which rings the eye and contracts when people produce genuine, but not polite smiles.?
Differentiating between the two can be difficult, though, says Dr. Paul Ekman, a professor emeritus of UC San Francisco who helped develop the Facial Action Coding System to help scientists distinguish between genuine and fake smiles.
?If it’s a very large smile and the lip corners are pulled up intensely then all of those signs will be produced by either a genuine or a non-genuine smile,? says Ekman, author of numerous books about facial expressions and how they reflect our emotions.
?The only place that will reveal the difference in a broad intense smile is the skin between the eyebrows and the upper eyelid. That will move slightly down in the genuine smile and will not move in the social or false smile. Everybody can voluntarily make their lips smile, but very few people can contract the muscle that surrounds the eyes.?
Source: I can’t find it right now! 
All I can say is… good timing. 
I have successfully tried: knuckles, temples, earlobes.
You can also go take a look at thermograms of the face and body for ideas.
http://www.pheromonetalk.com/attachments/pheromone-theory/1016d1391202739-spraying-pheromones-face-emotions_thermal_1-jpg
image credit:Another Side of Architecture: affective and emotional architecture: // making an emotional place // (a GREAT blog!)
Which would give you ideas, indicating, maybe the forehead is a good beacon for pheromonal action. People tend to kiss and sniff foreheads after all. And a kiss is a prolonged sniff. Now, A Kiss isn’t Just a Kiss.
I would take it with a grain of salt, though – as thermograms are different per each person!In the mid-1990s, it was demonstrated by scientist Francine J. Prokoski that facial thermograms are unique to individuals, and that methods and systems for positive biometric identification using facial thermograms could be developed. …]
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Facial thermography works by detecting heat patterns created by the branching of blood vessels that are emitted from the skin. These patterns, known as thermograms, are highly unique. As a consequence, identical twins have different thermograms.
More here:** Explainer: Facial Thermography | BiometricUpdate.com
*Well, that’s enough from me right now. My email is chiming off the hook.
Great reports, mobo. You’re a true asset to the community. 