You shouldn't even try to for the same reason you mentioned there. It's fiction, which means different ppl have different tastes and preferences, likes and dislikes, regarding what makes a good story to them, and everything can happen.
If you like NTR, cheating, fem.prot games, good for you, have fun playing them... that doesn't mean everyone has to like the same type of porn games and fetishes you do tho. Same goes for us romance/non NTR bois, ofc. Different ppl, different tastes and preferences. It's that simple.
You like something simply bcz you like it and just that. Nobody owes anyone an explanation to why they think something's good or bad, the only exception being (IMO) when posting a review that is supposed to be feedback helping the devs realize what's good or where they need to tweak a thing or two to make the story better and other users see if they want to check out the game or not.
Since it's fiction,
technically, everything, except the most hardcore controversial stuff that's against the rules, of course, is allowed. Pick the games that tick most of, or all, your interests, and have fun playing them. Escaping reality, its bullshit and all the stress there so they can finally relax too is another good reason why ppl play porn games and why their tastes and preferences should be considered 'sacred' to them and respected by the others.
Yeah, that was a pretty weak reason to add cheating with her so soon into the story, when the MC, her BF, constantly being away on the see doing fuck knows what with fuck knows who would make it a better reason for seeing her fall into temptation, IMO.
Thing is, I find it pretty hard to cheat on her, Kayla's simply too good, the almost-perfect GF, which is why I also think the MC sharing her on the red/beta path with other men cuz his pee-pee's too small to handle her would be a more believable scenario than what we got. I also don't think there's anyone who'd sit there quietly without caressing their woman, slapping her ass, grabbing her tits and fondling them, pulling her hair, well, the usual shit ppl do when they doing their
business.
Getting caught sleeping with Yana could've been another good trigger for Kayla to be so badly disappointed in the MC that she'd be desperate to get payback and cheat on him with the first remotely interesting guy who approached to 'comfort' her, and by jumping from one dick to the next, she'd slowly but surely forget him and his weak, beta idiot ass.