Jason is an omega in a place where omegas are held up above alphas. (Could be his religion or society as a whole.) Omegas are seen as pure and holy, and can do no wrong. Everything bad that happens to them is never seen as their fault. Alphas, on the other hand, are seen as thoughtless people who can't control themselves. For this reason, they're always kept separated. And Jason prides himself on being even better than most omegas. That is until he runs into an alpha who absolutely ruins him, it can be consensual or not.
Jason/MC, ABO, purity ruining