Lactic acid

The burning senstation you get in your legs and buttocks after a really hardcore sexual episode.

after two hours of cunnilingus his/her tounge was filled with lactic acid.

While fucking her doggy style his ass and legs began to feel the effects of lactic acid and he could no longer stand

Lactic acid by Diddilly Doo doo May 24, 2006

My cheeks are full of lactic acid 

The act of laughing so hard that your cheek muscles' anaerobic respiration goes into overdrive and overflows with lactic acid as a result.

hahaha, alan you're so funny my cheeks are full of lactic acid.

My cheeks are full of lactic acid by a little laughter April 6, 2021