Throbbing Red Clitoris
Although I am a great lover of a clitoris I do not possess one. However even being sans-clit I have to guess that trying this and getting it wrong is going to hurt.
Much in the way that a guy attempting the same thing would inflict terrible damage on his testicles on meeting the newel post at the bottom.
Would it involve lubrication and/or pants with a sturdy gusset?