After reading all of these scenarios I can't get rid of the headcanon that Mycroft would be the perfect sterotype for Omegas, big and fat with ample hips, lots of children and very motherly.
But consider: chubby teen Mycroft becoming whip-thin, driven Mycroft who’s going to be a Special Agent and Fight a Lot
and then getting promoted to a desk job and panicking as slowly by surely he fills out, fattens up, his Omega side taking over now that he’s not working out 6 hours a dayand then he gets an Alpha and his twenty pound gain becomes fifty in two months. Nothing fits anymore but he can’t stop eating, and his Alpha’s behind him all the time, one hand pressing food to his lips and the other squeezing his hips, his fat arse, or slipping around to squeeze and lift his ballooning belly, praising him all the while
then he gets pregnant, and between how possessive his Alpha is, how eager to show the world that Mycroft has a mate more than capable of taking care of him, and his pregnancy cravings, and the urge to eat for two, Mycroft knows he’s never ever going to be thin again
