Smack your hands against your body repeatedly, mainly the torso to chest area, and continue to smack hands on body and say "hambooooniiinngggg" in Rigby's voice from Regular Show.
Rigby: HAMBONINGGGG
Mordecai: No...
Rigby: HAMBONING WILL SAVE YOUR LIFE ONE DAY!!!! It'll be like "what! you tried to mug me?"
*proceeds to hambone for 20 seconds*
Mordecai: NO! We're not doing that, okay!? Okay!?
Rigby: Fine...
When a guy gets a new girlfriend and suddenly never talks to any of his friends again. Regardless of how many times you call him, he'll just ignore your phone calls even if you have helped him out in the rough times.
Can also apply when a friend has got a new toy such as a sports car or new computer
hombobette is the female version
Bob: You heard from John?
Paul: Nah he hombobo'd me aint heard from him when he got the S5
Bob: Raas!