From the Mandarin "la-go", meaning "pull-grab", slang for 'pinky swear'.
The undying bond of friendship and trust. Made to signify that you dare not mislead or hide things from your closest friends.
If you make lago its for reals. Only a big douchebag would break it. The punishment for breaking lago includes humiliation and disgrace in front of all those around you, a feeling of worthlessness, and getting punched really hard. Don't break lago.
Lago's enemies include:
Make lago, Gabo!
Fuck that lago shit!
I made out with three fine honeys last night.
Really? Make lago!
*pinkies pointed out about to intertwine, suddenly that first chap sticks 'is pointer finger out (which is, in reality, Not Lago)*
That ain't lago!