Check the Left

(phrase) To look at the left hand of a person of interest or a person seemingly interested in you to assess if a wedding/engagement ring is present for information gathering. Hopefully this information will influence a person's decision, but in the situation it doesn't at least one has an idea what they are getting into.

A, "Dude she's super hot, why don't you go for it?"
B, "Bro, check the left, that rock is huge."
A, "So, she totally wants to take you home!!!"
B, "Tonight I think I'm gonna do the right thing and say no."
B, "btw, I've been down that road and it blows goat nuts."