Looking for an old story...

Sorry, this is mostly a male-male story, but this is the best place I can think of to ask. This is a story I read years ago and can't find anymore.

The "hero" is fighting another man in some sort of arena or ring. They're mostly nude. The last time they fought, his adversary beat him (and became champion?) by punching his two fists together with a delicate part of the hero's anatomy in between. (I'm sure you guys are cringing now!) The hero gets a rematch, and wants to perform the same move--sadly, the adversary has a steel sheath with spikes that slides out to protect his you-know-what just as the hero strikes. So that didn't work great for the poor guy.

Throughout all this, there's a red-haired female spectator who is flirting, kissing, and sucking both contestants, trying to distract them.

Anyone remember this and know where to find it?