troilism

Although this word should really mean wacking off to pictures of Deanna Troi from star trek tng. It actually means a sexual situation involving three people. But there's a subtle distinction between troilism and a threesome. In a threesome everyone gets some nooky but in troilism one person just watches either in person or via a video camera.

I suppose there's times when it's good to be in the minority.
Oh really? Name one.
Umm... Troilism?
- Iain Banks, The Business