Subway train 

A sex move when the two partners connect bum cheeks and then proceed to defecate into each others anus; if only one person defecates then it is called the Subway train, although if both partners decide to poo, then it is the Subway train collision.

Man 1: So how was the girl last night?
Man 2: Oh god no, she has a scat fetish; she wanted to subway train me!

Subway train by SubwayTrainn May 1, 2010

Bulgarian subway train 

The subway system in Sofia, Bulgaria. Opened on January 28, 1998.

He's riding in a Bulgarian subway train.

Bulgarian subway train by TidePodIngebrigtsen69 June 20, 2016

Bulgarian Subway Train 

When one sexual partner connects the rectum hole with another, and either one eject's feces into the other's rectum. The other partner, who has received the feces, will excrete it back into the partners, along with her own. This will happen back and forth, making the Bulgarian Subway Train

The Bulgarian Subway Train was very gross, so said the viewers. They also listen it as being 'vile' .

Bulgarian Subway Train by Hamachis October 24, 2010

That one dude who took my subway at train station 

That damn son of a b#tch he will fu#@ing pay for this damn yooooooouuuuuuuuu!!!!!!!!!!!!!

Well That one dude who took my subway at train station will f@cking pay

That one dude who took my subway at train station by Dizzlenuts April 21, 2018