Rusty Leaky Locomotive

This is when you stand infront of your toilet naked while your female partner (unlike the regular Leaky Locomotive hangs on your shoulders facing you. As you Initiate vaginal intercourse your female partner takes a dump in the toilet.
*Warning* This can get very dirty.

Rusty Leaky Locomotive:
Bob: "Dude it go so messy last night!"
Frank: "messy, why?"
Bob: "We did the Rusty Leaky locomotive!"
Frank: "Woah!"