I GIVE UP
I found this fic on spnstoryfinders, and though I have searched, I cannot find it again, so I'm that person who asks for a fic that is clearly already on the com.

King (maybe Prince?) Jensen is cured to bear an heir for his kingdom, so every year his council holds a tournament for all the eligible royals in the region. Every year the winner tries to get him pregnant, but it never catches. Meanwhile, Jared is the leader of this destitute nomad tribe who everyone on the continent hates because however many generations back they made a deal with some magic wolves or something and now have certain wolf traits; one of which is impressive fertility, this is where the knotting comes in. Jared goes to ask if his tribe can stay in this valley with streams for a few weeks that is on Jensen's land, because they're all starving because they get run out of everywhere and no one will trade with them. However, he accidentally gets sucked into this year's tournament.

Someone please I love this fic endlessly. *kowtows*

FOUND: http://morrezela.livejournal.com/107912.html
(and of course it's morrezela, as are most good things in life)