Timeline Season 8
Sam and Dean aren’t related in this fic. Sam’s parents died when he was young and the Winchesters raised him. There is dub-con, but only in the sense that Dean would rather not be the lowest in ranking and it’s not really dub-con regarding the sex, but please read with caution if you are sensitive to such things. The behavior is normal in this society and part of the A/B/O dynamics.