Popularized by the Dc animated show "Young Justice." It is used when someone realizes something that was really obvious or finally solved a mistery.
Violet: "you knew she was into me? Since when?"
Terra: "Hello Megan, she's been crushing on you for a year. "
Terra: "Hello Megan, she's been crushing on you for a year. "
by RandB July 7, 2022

A punch to the face, especially of a random person you encounter in Boston or the kingdom known as Red Sox Nation
by whothefuckcaresaboutahandle July 25, 2016

The hello and goodbye is a routine usually preformed by a girlfriend or wife where she both starts the sexual encounter with a cock in her mouth(hello!) and ends the encounter with the same cock in her mouth(goodbye). (In between that period she is fucked lavishly) Just a standard blow job does not count as a "hello and goodbye".
My wife woke me this morning with The "hello & goodbye". And then she went to work and I went back to bed.
by Bangin the cart girl July 16, 2014

"If you take another step into my dojo, i'm going to have to show you what it means to experience the The Tōtsuki Hello"
by Burred March 21, 2018

by VictorianGunsel February 1, 2018

by friskat3am_ May 25, 2022

Jim: knocks on Goodman's front door hoping to see Jackie
Jackie: Opens door
Jim: Stares at Jackie for 10 minutes
Also Jim: Hello All!
Jackie: Opens door
Jim: Stares at Jackie for 10 minutes
Also Jim: Hello All!
by cely:))) June 8, 2020
