The process of putting a finger in a girl's vagina then subtly bringing the finger up to your nose and smelling it. Is done in order to determine if the girl smells good enough to go down on.
Thank god I used the dip n' sniff test on that girl I brought home last night. My finger smelled like I dipped it in the frylator at Red Lobster! Needless to say, my face went no where near that pussy.