As a distraction modern au thoughts, but even when in denial, Vash has very erotic dreams about blowing Nai's uncut dick. And nightmares where Nai says he's going to get circumcized. one time he's sleeping over and Nai hears him screaming his name in his sleep so he shakes him awake, and Vash is all teary eyed and upset but won't tell him why (also later Vash does surreptitiously check to make sure the snuggie is still there)