Combination of "checking someone out" and "the checkout" (as in the check out line), describing the slightly invasive act of checking out the items in the shopping cart of the person behind you in line at the checkout.
Bro 1: Did you see that? She was checking me out.
Bro 2: No, Bro, she was checking out the things you're buying. The checkout check out ain't the same thing.
Bro 2: No, Bro, she was checking out the things you're buying. The checkout check out ain't the same thing.
by Ae5Ea8 March 2, 2015