That patented move that girls (and some guys) do in front of a mirror to see how good their ass looks in the jeans they are trying on. Involves craning neck backwards while pivoting on one's toe.
I felt like the dutiful boyfriend while she did repeated booty checks in the mirror at H&M.
a swift, playful, yet ferocious flick aimed toward a friends genital area if you suspect him of having an erection within no vacinity of the opposite sex.
walked past fred, something brushed against me, and it wasn't a gun,he was obviously too pleased to see me so i issued a boabycheck.