Two feathered flappers came together,
Panting and pushing in the open air.
The bright-haired girl, flushed and proud,
Grew big in the belly if the work was good.
Now scholars may need these letters to know
What I'm talking about: O and C,
N and E, K and H, and another C.
The tumblers twist to the letters' key
As the treasure-door swings open
So that solvers can see in the heart
Of the riddle, craft and play. Carousing men
May know the names of the low-down lovers!

I have tried and tried and I must say that I am truly stumped.

It is a cock and hen. I was stumped too - was looking for a different bird. I shared your Chelsea Clinton joke with my oldest son and he nearly died laughing. He said you might have something there. Lol

A cock and a hen. I have chickens out back and I was sitting here trying to figure it out while looking right at them!