while getting your dick sucked, this is when the female (because gay cock sucking is just gross!) takes her tounge and flicks it on the underside of the head (flickulum) here loose skin is.

when done properly this is called the "butterfly flick"
Derek: Man that chick last night flicked her tounge on the underside of my head with a smile on her face just before she took the whole thing!

Scott: What a champ!

Derek: Yeah, i didnt know she knew how to do the butterfly flick!
by D-Rock5489 October 24, 2011