Swallowback 

(Noun) To vomit a little in your mouth, and then gulp it down again, usually as the result of seeing something hideous. Can also be used as a unit of measurement in extreme cases.

Guy 1: Did you see that girl's beergut spilling out under her top?

Guy 2: Yes i did, gave me two gulps of swallowback.

Swallowback by andreijizzek July 31, 2010

swallowcock 

When your girl inhales your entire dick

Im still sore from that swallowcock yesterday

swallowcock by Meguil August 10, 2016

swallow back 

1. The term represents giving a blow job and taking in the semen

I told this chick to swallow back, and she took it all.

swallow back by King of NY August 10, 2006