FOUND - looking for specific a/b/o Destiel dragon fic
Lost this fic and NEED to find it again. omega!Dean enters into an arranged marriage to Castiel's son, who wants nothing to do with him. Instead, the marriage is consummated between alpha!Castiel and Dean, in a slightly dub con way in that Dean wasn’t expecting to lose his virginity to his husband’s father. Cas' son continues to avoid Dean and the relationship between Dean and Cas grows, and eventually Dean gets pregnant by Cas; at which point Cas marries Dean himself.
*SPOILERS*
It turns out Dean is a hunter who willingly becomes part of what we find is a dragon family (though they do not shift anymore and are mostly human). In the end he decides it’s not necessary to kill the family. It also turns out coincidentally that Dean's mother was part dragon and passed on those genes, meaning any children he might have with Cas would be more powerful. There’s also a powerful omega!dragon!grand-mother in there somewhere.