To 212 or to be 212in is to step away from a group of friends your chillin with with another one of your friends to have a private conversation with
"yo C come 212 with me real quick"
"aight whachu need nigga?"
"lets dip outta here and smoke a Nice L just me and you in the shed"
* done 212in*
-steps back to the group and explains they both have to leave-