some omega!mack headcanons
hot-headed. omegas can be scrappy!! all of mack's emotions run on high. he feels things intensely, burning hot then quickly fizzling out. he's scrappy, and snippy, and a brat. omegas are fiercely protective of their pack, mate, and pups. and mack is no different. he tries to control his emotions more with strangers and his team. heโs kind and polite. but with will, he can really let go. will can take it, and heโll like him anyway.
stuck in the puppy phase. he's still held on to some puppy traits, things he never grew out of. teething, for one. constantly chews on his mouthguard, his hoodie strings, his own fingers. just needs something to bite, to suck on. he's possessive, and defensive of what's his, in the same way a puppy lacks object permanence; he worries it'll be taken away and gone forever. people sometimes mistake him as an alpha for these things, but he's really just an overgrown pup.
doesn't know how to nest. between an adolescence toning down his instincts to seem tough in an alpha dominated sport and traveling constantly for hockey, he's never had a real nest. (maybe rick thought a nest wouldn't be sustainable with the traveling demands of professional hockey and taught mack not to be reliant on a nest). it's not until will that his instincts scream for him to surround himself in will's hoodies and shirts. he has this undercurrent of anxiety, and someone recommends nesting more often (oblivious to the fact he doesn't at all). but he doesn't know how. people online just say to do what feels good, but he can't figure it out. each time he tries ends in tears, and makes him feel like a broken omega. will notices mack's tired eyes. the way he curls in on himself. his uncharacteristic quietness. he asks what's wrong, and mack explains, reluctantly. will had noticed mack doesn't really nest, and was confused by it, but let him do his thing. now he understands why. so he calls his sister and his mom and at least three other omegas for advice and recommendations. books mack a private consultation appointment at a luxury nesting store. they build it together, and mack is glowing. he nests all the time now. he gets the best sleep of his life, cuddled up in his nest with his alpha.
his purr. similar to the nesting thing. he's never really stopped for an extended period of time. always go, go, go. inadvertently, and beyond his knowledge, his body has been in a perpetual state of stress since he was thirteen and first left home. omegs purr when they feel completely safe, entirely relaxed, and content. the first time he purrs, it's in his sleep, burrowed under blankets and propped up on will's chest. it's broken and weak, but the very first beginnings of it are there. as he settles into his new life, new relationship, he learns how to slow down. that there's more to life than hockey. learns how to nest, how to nurture his own instincts, and it grows, gets fuller and stronger every day. (the cartilage necessary to produce a purr will likely always be damaged, causing the vibrations to falter and crack occasionally, but it's unique and something distinctly mack)
his scent. his base scent is milk chocolate and freshly brewed coffee. extreme emotions build on top of his base scent: when he's really happy, it goes even sweeter, with whipped cream and marshmallow. goes bitter, when he's angry or upset, like burnt espresso. cinnamon and warmth, when he's in heat. mack never cared to learn how to control his scent. if he doesn't want people to smell him, he'll wear blockers, as simple as that. everyone knows he's an omega, it was a whole thing when he was drafted and continues to be a thing as he excels, so who cares who can smell him?
he's unregulated. this doesn't help his emotional control at all. his hormones are all out of whack thanks to years of suppressant use (so he doesn't have to go on heat leave and miss games). doesn't scent, doesn't nest. his body is in a constant state of red alert. he's on the verge of going feral. once he does start doing omega things, it's a world of a difference. he feels so much more calm. he's still himself, of course, still independent and headstrong and stubborn, but has ways to cope with his big emotions, his instincts have somewhere soft to land.
baby fever. mack would insist he's not particularly maternal (he's wrong). he loves kids. loves chasing patty's kids in the backyard, helping jumbo's kids with their math homework. his face lights up when he gets to hold woody's baby for the first time, and he coos at her with starry-eyed wonder. he adopts the rookies, checks in on all his teammates, no matter how much older they are than him. is constantly cheering everyone on with targeted, specific compliments. reassurance, when a puck bounces out. he's definitely planned out the next fifteen years. how to alternate cup runs and olympics teams with baby bottles and nurseries. when to get pregnant, so pregnancy and recovery are strategically in line with the hockey season. he's used to having his life planned out years in advance and it works. he's being sensible and mature. but when he sees will with a baby, it's over. watches him push a stroller for his agent and play barbies with ned's toddler and just thinks fuck the plan. he jumps him, when they get home. will has to be the sensible one, and it takes every ounce of his willpower (ha) to do so.
afraid of being weak. he doesn't hate being an omega per se. there's some things he views as negative, of course. painful heats, for one. he mostly hates the way other people view him. the way his dynamic is this big thing in the media, but status is never mentioned when it's an alpha or beta. doesn't like how people assume he's weak or delicate. that he can't take a hit. that he's slept his way to the top (like that's even possible, his stats speak for themselves). so he hides away his omega traits, sometimes without even meaning to. is private about heats and relationships. pushes himself harder and harder and harder so no one can question why he went first overall. first one on the ice, last one off, always. it takes him a while to learn that he's good, the way he is. that it's admirable to work hard, but he shouldn't destroy himself in the process. that everyone knows he's good. and if they have to resort to his dynamic to debate that, it just means they have no other argument to make.