Recently run across by accident, a reference to a Kindle “book” (apparently a self-published manuscript) entitled “How to cowboy up and stop being such a pussy” by “Max Powerz”. The author’s description:
A much needed guide for many men who have evolved into being unable to change a tire, cook a steak, kill a rodent, or God forbid, say a naughty word..
And the cover:
Note the pink panties, a symbol of what happens to the man who doesn’t cowboy up. The dreaded specter of feminization.
The idiom cowboy up here seems to be man up on steroids. (On man up, see this posting of 8/11/13.)