What is Flying Scotsman?
1.
A sex position in which someone lies on their back with their feet firmly placed on one's pelvis, either side of the penis. The legs are pointed strait up, hoisting one high in the air. One would jizz on one's partner, while wearing a kilt, with one's arms out at one's side, making one, quite literally, a flying scotsman.
Yo dude remember that scotish chick we met at the bar last night? Yeah, we went back to my place and she gave me a flying scotsman!
2.
A highly complicated sex act that isn't worth the bother.
Not worth the bother.