1. Code for blow jobs by numerical order of the alphabet (i.e. "b" is the 2 and "j" is the 10).
2. An idiot's way of saying that he's 420 tolerant in a personal ad.
Guy 1: Dude, so this potential roommate on Craig's list says they're 210 friendly. I don't know if I can trust that.
Guy 2: Why? You're the biggest gay stoner I know. What could be the problem?
Guy 1: What if it's a chick?