*Clouds*

Like, omegas with alpha instincts basically, and alphas with omega instincts, along with extra omega-y omegas, and extra alpha-y alphas, if that makes sense. Normal alphas betas, and omegas are more common in this universe, of course.

Dominant alphas are the rarest. They're the most aggressive, don't get along with other alphas, and their instincts are all ramped up.

Submissive alphas are a lot more like betas, but they have an alpha's protective instincts and such. They're more mellow and least likely to fight over stuff.

Dominant omegas are super protective of things and behave a lot like an alpha, but they're not quite as aggressive. They're more likely to take up an alpha-like role in relationships, and don't typically pair with alphas.

And submissive omegas are also pretty rare. They're very instinct driven, and most of them end up with stay-at-home roles.

Hopefully that makes sense? Idk, anyways, Gracebert:

Dominant omega Robert/omega Grace.

When they wake up on the Hail Mary, neither of them really pay attention to their dynamics. For Grace, he's so focused on remembering things and fixing the astrophage issue that he kinda forgets about it. And for Robert, he was never in tune with his omega, so he didn't think he'd have to deal with it.

Then Grace's heat starts, and Robert's instincts immediately come to life. He's protecting Grace's nest (from nothing), fetching things for Grace, and just generally acting like an alpha to the point where Grace thought he was one.

And then his heat triggers Robert's heat, and he's completely thrown for a loop.

Then they become mates and both of them help regulate one another's omegas. Rocky thinks they're total weirdos.