nippin' it 

hard nipples caused especially from cooler weather, THO

That chick over there is nippin' it.

nippin' it by Chris July 29, 2004

nipplin' it 

When a musician, especially a bassist, has their strap adjusted in such a way that their instrument and thus strumming or plucking is at nipple height.

"Man, the bassist plays his bass up high. Really nipplin' it. "

nipplin' it by Musicianman December 9, 2013