tongue flicking 

the spontaneous act of flicking your tongue up and down in a sexual motion. people with small tongues cannot complete this act. also very good for performing sexual favors.

emily sucks at tongue flicking because her tongue is too small. don't pay her for a shitty blowjob.

tongue flicking by soberhoursisters September 7, 2016

Tongue flicking 

When you flick you tongue up and down on a girls clit

Guy1: how was the sex?
Guy2: really nice, she likes it when I do the tongue flicking trick

Tongue flicking by Tetreslove April 23, 2018