Nathan's hand stays exactly where it is. "Am I trying to win or do science?" he asks.
He keeps increasing the pressure from his side. It doesn't go up as smoothly as it would with a vampire, but he's definitely getting into vampiric range.
He switches goals from "keep hand where it is" to "slam Aianon's hand onto the rock". This isn't as automatically decisive as it would be with any non-supernatural strength, but it is sudden and forceful.
Their joined hands sway abruptly in one direction, and then somewhat less abruptly in the other. Aianon doesn't have perfect control of exactly which muscles are exerting how much force; he crushes Nathan's hand a little.
"Sorry," he says, flicking his tail from side to side, and tries to squeeze less. Which also leaves their hands more or less vertical.
"Although the fact that you can meaningfully squeeze my hand is interesting," comments Nathan, still pushing.
"Is it?" he wonders, still pushing back. Their hands waver back and forth a little; the force he applies isn't consistent.
"Yeah, at home vampires can be hurt by three things. Vampires - or our relatives, if they get a chance - and werewolves and fire." Pause. "Starvation can also get us but it's slow. Usually."
"Demons can be hurt by many things, but killed by few," he says. "Unicorns. Certain magics. Unicorns no longer burn me; I have not tried the other."
Nathan kisses back. His distraction does nothing to lessen the force of his wrestling arm.
The demon laughs. His distraction makes him forget not to squeeze, very very briefly before he remembers again.
"Newborn could probably beat you outright," he comments. "Newborn's at least half again as strong as me."
"I have not fought one of my own kind in thousands of years," he says. "Now I am glad I will not have to."
"Well, if you win - which is looking increasingly unlikely - we can see if Emmett wants to come try, he's probably strongest of anyone who might show up to a peal party."
Their hands are wavering over to his side more frequently. It seems his arm is getting tired.