I imagine, Enjin is allergic to domestic scenes.
That's why he chooses to have one night stands instead of dating life. He isn't obligated to "stay after" and taking care of them.
Towards Team Akuta, it's different though. He considers them his family, so doing standard house chores doesn't feel domestic to him at all. It's just natural.
Cooking for them? Easy peasy.
Taking care of them while they're sick? Well, he's not Eishia but he won't waste the golden opportunity to chide and fuss.
Watching over them? Someone's gotta keep an eye on those brats.
Until, he's getting together with Zanka.
Suddenly, he wants to do everything with him, for him.
Going out for groceries? Well, Zanka can accompany him and help him with things to buy.
Doing the laundry? He's not the most organized person on earth, but if Zanka tells him he should separate his clothes based on the colors and materials, maybe he does have to.
Finishing the reports on time? Good for Semiu, if Zanka can help then she won't be riding on his ass anymore.
Keeping everything in his room in order? Zanka's right, he can find things he wants to find easier that way.
I think, Enjin settles into domesticity so easily, because he already does it before, Zanka's presence just amplifies it.
So if anyone (be it Riyo, Rudo, Gris, Semiu, or literally anyone) notices that Enjin has changed for a better after he's together with Zanka, Enjin is probably looking at them funny like, "What do you mean, I always do those things?"
Yeah, of course you, you just don't make it into your habit, until Zanka comes into the equation.
#enzn random thought
Enzn's forehead kiss.
Enjin closes his eyes and lingers, let his lips stay as long as possible on the warmth of Zanka's skin, hand still itself parting the hair for access.
Zanka closes his eyes, savoring the touch, hand clings to Enjin's coat for composure.
When Enjin steps back, he looks down only to have Zanka already looks up at him.
With those beautiful azure of his, with that kind of smile he reserves only for Enjin, and seeing all that, it's just natural for him to lean down and steal a kiss or two.
But, honestly, it's still considered stealing if Zanka gives them away?