steam tunnels 

Underground tunnels made to deliver heat (in the form of steam) from a central heating plant to multiple buildings. Commonly found on college campuses. Often retrofitted with wires to deliver electricity or telecommunications. Sometimes used by students or other adventurers for recreational purposes, see urban exploration.

We found an open hatch that led into the steam tunnels, and spent a few hours exploring the campus from underground.

steam tunnels by Professor Slats November 1, 2008

steam tunnelling

The act of hot-boxing a partner's anus

Bitch was so fugly, I had to go steam tunnelling before I could fuck her.

steam tunnelling by Christina Farah February 3, 2007

Steam Tunneling

Farting under the covers and using a knee and elbow to direct the exhaust to your partners face when they are above the covers. Similar to a Dutch oven.

The best way to air out a fart in bed is by steam tunneling

Steam Tunneling by TheBrasky May 16, 2019

Chinese Steam Tunnel 

The act of deficating in someone elses anus

I totally Chinese Steam Tunneled that Elouise last night!

Chinese Steam Tunnel by KathleenRocks January 26, 2011

tunnel steamy

Take a fart like a bong rip from a sex partners anus.

I gave my girl a tunnel steamy last night and now my breath smells like butthole.

tunnel steamy by SomeDumbNerd March 17, 2016