To fail notably to impress or excite somebody; a feeling that someone gets when it is obvious that the other party has put forth little or no effort to gain your love or affection.
Ericka: During Jud’s absence, both Stephen and Bob contacted Janine. Stephen made reservations for lunch at her favorite restaurant, greeted her with Godiva chocolates, apologized profusely for not calling her, and stated he was an idiot. Bob met her at Panera, and didn’t even offer to cover the cost of her coffee.
The UnderJoke, sometimes called the "Hover" or the "Secondary Joke," refers to the second laugh line found at XKCD.com if one hovers their mouse over the original cartoon.
When I read the underjoke for today's cartoon, I laughed so hard that snot came out my nose.
when you're holding up your phone and making faces at it, as though you are taking a selfie, but you're really taking a picture of the person across from you or the wall or anything else that seems interesting but you don't want to be caught dead taking a picture of.
This action is often made more convincing by wiggling the eyebrows or opening the mouth, to pretend you're trying to get a Snapchat filter to work.