skin tits 

A woman who’s so flat chested her nipples are the only thing that stick out

Wow look at Jackie she’s so flat chested she’s got skin tits !

skin tits by Jackiejim April 4, 2019

by the skin of my tits 

A funny version of the classic phrase " The skin of my teeth" but replace the teeth with tits

Holy shit man ! I just got out of there by the skin of my tits!

by the skin of my tits by Tacos 'n Tits March 5, 2017