Years ago, Napoleon had complained strenuously when Sanders had strong-armed him into the CIA’s training classes for alphas. He was in the prime of his life and no longer some sort of schoolboy, easily turned by an omega’s seasonal pheromones, or so he had said at the time. Now the training kicked in, and Napoleon breathed a little more rapidly and through his mouth, to dilute the effect. Illya seemed to notice, smirking faintly.
“You’re an omega,” Napoleon grit out, once his head had cleared a little. “That wasn’t in your… I thought you were null.”
“Very rude thing to say. We are in public.” Illya said dryly, which was true.
Source: Tiger, Tiger, by manic_intent – The Man From U.N.C.L.E. (2015) [Archive of Our Own]
This might be one of the few fandoms where I actively seek out A/B/O fics, just because Illya will never be a wilting flower. 😉 This one is excellent because it very much plays with the expected gender roles.