I stumbled one day across two dogs,
screwing by the sea.
When upon this scene there came one more,
and he opted to make it three.
This envious cur - so cocksure,
decided to claim his prize.
With gender aside, he took 'em astride,
and gave him a surprise.
This once lucky stud, torn from his pride, 
attempts quickly to abort.
But all's too late - it's futile: 
he's tied the knot - stuck in this cohort.
His once wondrous claim, now pain and shame;
made bitch upon the sea.
That which was so great where there were two before,
ended when it became three.