Extreme happiness in many forms. Mostly to do with sexual pleasure or getting laid. Can also be used when something exciting (sexual or not happens). Often screamed in happiness(or in orgasm).
Woman: Are you close?
Friend 1: OH MY GOD STAR WARS IN CONCERT!!!
Friend 2: BONNIWAY!!!!!
When a man cums in a girls mouth after head, he swishes his "meat" (penis) around in her mouth while the cum is still unswallowed or not spat out in a rotational circle as the blades of a blender would do, causing a meat smoothie.
A meat smoothing is literally when you mix the smoothie (cum) with your meat (penis).
Girl: I was with my boyfriend last night and he gave me a meat smoothie. I could taste everything, it was fantastic.
Guy: I'm going to put my meat in your mouth and make a smoothie with my juices.