After fucking a chicks yatch hard (preferrably in the doggy position), you proceed to flip her on her back, grab her by the ankles, bend her knees to her chest, and make her queef. Repeat this maneuver by pumping her legs as if you were playing a tuba. "Ruda" is short for Rudimentary.
After I gave her a good old fashioned holiday rogering, I wailed on the rudatuba.
A sexual move in which a man's limbs are bent in every which way until he resembles a human pretzel (they may break), and the woman puts her mouth around his dick (likeone would a mouthpiece) and blows. This will tickle the man, and will make him giggle like a japanese schoolgirl
"Last night was the best. I got a the japanese tuba from this buff russian lady and I had to go to the hospital afterwards ."