Title: Scent and Sensibility
Length: 39,000 (complete)
Summary: In a world where most people identify their mates by scent the first time they meet, Kakashi and Iruka take a more scenic route.
Or, the one where Iruka does an excellent job of hiding the fact that he is an omega, right up until he gets stuck in a cave with Kakashi.
(A/B/O dynamics but without mpreg, dub-con, rivers of gushing fluids, monster cocks of doom, and also trying to avoid overt sexism and overly stereotyped gender roles.)
Link: On AO3 here