An M. Truby may not be a well known sexual act, but there is reason for its obscurity. To put it lightly, the M. Truby is the most disgusting sexual act known to man. Those who have received one of these sexual "favors" will either never speak of it to another human being, or commit suicide immediately following (or during) the act.
The M. Truby is believed to have started in the early sixteenth century, but scholars are unsure because no one who has received an MT has ever spoken of it to anyone. The M. Truby has been the cause of sixteen celebrity suicides, two presidential deaths, and the Holocaust. This vulgar display has been banned in most countries around the world, and has even been used as a drastic form of torture.
Disclaimer: Many people who have read even the meaning of this sexual act have died by choking on their own vomit. Read further at your own risk.
An M. Truby, I regret to say, is any sexual activity involving a ginger.
Todd: Hey, have you ever heard of something called an M. Truby?
Jim: What? Me? No... no, not me, man. Definitely not. Not at all. Never even heard of it. Psh you joking? Don't make me laugh. I don't even know what that is! Why who told you?
Todd: Gross, dude.
Jim: You tell anyone, I'll kill you.
Todd: We're not friends anymore.