His parents always told Jack he couldn't became an officer of the law because he was an Omega. They told him he was too delicate, too important to risk his life tracking down rapists and murderers, that given the opportunity he would end up a victim of those same criminals. His father told him to find a career and pursuits more in line with his station, that he should register with the Alpha-Omega Agency as an Omega and attend the 'Meet and Greet' receptions until an Alpha paid enough interest in him.
Jack left home soon after, and took suppressants, allowing him to pass as a Beta to the rest of the world. He wasn't academically bright but he excelled at catching criminals, and that was all that counted when he applied for the U.S. Marshals, lying about his dynamic on the application form. Some of the Alphas looked at him askew but the suppressants kept his Omega scent mostly concealed so they usually shook their heads and moved on, treating him like any other Beta Law Enforcement Officer. He met Abby by chance and everything was great until she began to suspect there was something wrong about him. She was a Beta and she did not have the same heightened senses as Alphas and Omegas but Abby was clever and also tenacious so it became easier spending days, weeks, on fugitive hunts rather than going home every night. His only regret was knowing how much Zoe blamed him for his absence, and once she started acting out to gain his attention the arguments between him and Abby grew out of all proportion.
And then Abby found his small stash of suppressants.
He hated the look of betrayal in her eyes, as if he had done something terribly wrong when all he had wanted was a normal, average life. Part of him understood her anger for if he ever crossed paths with his One True Alpha then she would lose him as soon as the Alpha recognized him as his or her One True Omega, and if that Alpha was already with another Omega then that relationship would suffer too. It was a no-win situation for all of them.
"And that's why I'm suppressing the Omega."
He tried to explain but Abby wouldn't listen so maybe it was for the best when he got a 'promotion' to the weird town he and Zoe landed in after he tracked her down for the third time. Jack moved out alone.
'Sheriff Jack Carter' had a certain ring to it, and a better salary, but it still felt more like a demotion.
On his second day on the job he met Doctor Nathan Stark, and if there was such a thing as a 'Super Alpha' then Nathan Stark was it. There was also something incredibly arousing about him but Jack reined in the desire, focusing instead on the relationship between Allison and Stark. He didn't need to scent the highly charged emotions to know Allison was angry with her estranged husband, and fortunately that deflected any flare of interest Stark had in him. Jack got out of there quickly, determined to limit any contact with Stark to the bare minimum - and maybe up his dosage of the suppressant to be on the safe side.
Of course Stark's irritation with him over Allison helped divert the Alpha's attention from what was really driving Stark slowly insane, unknowingly. Except Jack knew it was affecting him too. He could feel the pull towards this one person and in his heart he knew Stark was his One True Alpha, and he hated it. Jack had spent half his life suppressing the Omega side of him, and now his very nature was slowly and surely betraying him because that part of him wanted Nathan Stark.
Everything changed the day Weinbrenner started up his Photon decelerator and caused a time loop. The time loops messed with his body, and on the final loop, having persuaded Nathan by reciting the time equation to the tune of a children's song, he had to stand by and watch Nathan step into the time chamber when the seal failed. Before the door sealed closed Nathan sniffed at him, eyes widening as Jack's Omega scent hit him. Confusion, anger, and regret followed in swift succession, for both of them.
Jack saw Nathan freeze inside the chamber as the Photon accelerated. He watched as Nathan began to dissolve into tiny sparkles and his heart started to break at the loss. He barely noticed Fargo leaping into action, pressing buttons, typing rapidly, and flipping switches but suddenly the sparkles began to recede with Nathan re-forming before his eyes.
"I did it!" Fargo crowed, but Jack wasn't convinced until Nathan blinked and shook his head, not until he stepped out of the time chamber and, ignoring Fargo, walked straight up to Jack.
Nathan leaned in and drew in Jack's scent before pulling back.
"Why?" he asked, and Jack shrugged.
"You really need to ask?" Jack retorted. "I'm the Sheriff, not some..." He trailed off, unable to find the words to describe how soulless his life would have been had he chosen to be a typical Omega. It hurt to say it, and he knew he would have to live with his decision but, "I can't be... that. What you'd want me to be."
He glanced across to where Fargo was looking between them, totally confused, feeling worried in case Fargo put it together and realized Jack's secret.
"You don't know what I want from my Omega, Jack. And what you want doesn't have to change," Nathan stated. "I won't ask you to resign. You can carry on... sheriffing," he added with a small, mocking smile that held humor rather than malice. "But I do want you to give us... to give me a chance."
By now Fargo was wide-eyed, finally understanding. "Doctor Blake!" he exclaimed, reminding both of them of the wedding ceremony awaiting both its groom and the man who was supposed to give away the Bride.
"There won't be a wedding. I can't remarry Allison knowing what I know now. Yes or No, that doesn't matter, Jack." He shrugged, "Though I'd prefer a Yes."
It was a gamble that could backfire heavily if things didn't work out with Nathan, but Jack knew he had to take the chance - for both their sake.
He nodded and smiled, and he never looked back.