Orgasmic Mutation

The act of nature imposed on a human mid coitus, transitioning genes into a primal form, essentially transforming the host into a beastial form.

(The words "orgasmic mutation" was created by me and if it weren't for my messed up friends I'd never have a definition)

"Yo! Did you hear about Brian?"

"No. What happened?"

"He was fucking and had an orgasmic mutation!"