I need to go through every little detail of Wymacks POV in the extra story of The Foxhole Court because that man is the most caring and loving human being the foxes could have encountered.
In the next quote Wymack is really trying to be neutral be he only can see the life he could have had with Kayleigh:
Now Kevin was a devastated wreck on David's couch. David had to be neutral and unyielding, but Kevin would always be different.
This man thinks Kayleigh left him for another man and that Kevin is not his son. Kevin is a condtant reminder of Kayleigh loss but he wants to keep him close because of this. And then he throws this to a drunk panicked Kevin:
"You're not just a Fox," David said, before he could think to stop himself. "You're Kayleigh's son"
How doesn't Kevin tell him right there that he is his father? Nobody knows my man was too occupied spiralling about the Moriyamas and Riko.
But the thing that brokes Wymack's heart is seeing a pure reflection of Kayleigh's be so washed out. He wants Kevin to be the best version of himself, he wants for Kevin to be as passionate as his mother. Wymack is the only person who can tell Kevin about how Kayleigh was while she was alive, adding memories to a child who lost a mother at 9.
Jesus, Kevin looked so much like her, except Kayleigh had never looked so defeated and afraid. She'd been fierce and vibrant and fearless.
Wymack knew Kayleigh didn't want ties or commitments with him so he run away before putting her in a situation where she had to choose.
He'd promised to keep it casual, but it hadn't stopped him from falling for her. When he started thinking about rings he put himself on a plane home.
Should have, could have, what-if.
We don't know wether if Kayleigh trurly would have had a relationship with Wymack if he stayed what we know is that she is probably one of Wymack's biggest regrets/question. Maybe if he stayed they'd have raised Kevin, maybe not. We don't know even if she would have told him Kevin was his in that scenario. We know nothing about her besides what Wymack says.
"Coaches have no honor, your word is enough. Just yours."
Then Kevin drop this and Wymack is startled because it implies so much. Kevin was not just abused by Riko but also by his coach so trusting a similar figure should be hard. Kevin doesn't trust Wymack because he's his father either. He trusts him because he sees how much he cares for the foxes, he sees how much he tries to protect him without knowing who he trurly is that is why Kevin is capable of handing Wymack his life.
David wasn't a praying man, and he'd never quite decided whether he believed in an afterlife, but for a second he glanced up at the sky in search of Kayleigh's disapproving glower.
"I'm sorry,"
Even though Wymack is doing his best he still feels like he is not what Kayleigh would have wanted he feels he has no redemption regarding her. He is taking care of Kevin yes, but he feels like Kevin shouldn't be in that position to start with. If he cared enough before she died maybe her son wouldn't have ended up tortured. Maybe if he weren't angry/disappointed when Kayleigh was pregnant he could have been around and prevent everything from happening. These are some of the what-ifs that keep David awake and that would never have an answer. He could never regret enough the time he lost with her.