Perfect Surprise (слэш)

Shane has always been a soft Alpha, but all the years he spent sleeping with Ilya, a dominant Alpha, unknowingly caused his body to change, turning him into an Omega.
He doesn’t know how to feel about it; he doesn’t mind, but surely Ilya won’t want to be with an Omega when all he’s ever been with are Alphas.
Or, Shane is now an Omega and hides it because he’s worried Ilya won’t want him anymore, but what he doesn’t know is that Ilya loves him for him, and it’s not going to change anything.