A situation where you are expecting something for a long time, and not only do you not recieve it, but you also get no explanation.
(Derived from the infamous scene from Avatar: The Last Airbender where Zuko asks, "Now... where's my mother?" and the fans get NO RESPONSE after waiting 3 SEASONS.)
Megan: "...Hey, didn't Mr. Sommers promise us donuts this morning?"
Alan: "Yeah. He probably forgot. Talk about a 'Where's Mom Moment'."
A godly level roast that will leave the person dead.
Jimmy: I was eating your mom!
Bob: Well I was eating your mom’s mom!
Jimmy: Well I ate your mom, your mom’s mom, and your mom’s mom’s mom!
Bob: Your mom’s mom’s mom’s mom.
Jimmy: *freaking disintegrates*