Evulse
"Beansprout," he'll grunt when those hands start to pull his hair. The long strands will be dipped in the water and lathered with soap. He'll lean forward as the person behind settles and he'll fold his arms in his usually disgruntled fashion. He won't want to express his irritation, because he won't want this other person believing he's a pansy for the protesting he would otherwise do if he wouldn't be holding it in.
However, his partner will lack the gentleness and he'll start to feel the hair burning at the roots—threatening to pull loose. Teeth will dig into his lower lip and he'll move his head with every pull to ease the tension from the actions of his mate.
"What's wrong?" The boy will whispers in his ear and he'll swallow his protest before he can say it. Allen's attempt to be gentle will fail, but he'll let it and boil in the discomfort until the younger male is done seeding his fingers through the long clean locks.
"Nothing," the words will come out muddy and he'll turn his head back to his lap, where he'll fold his hands together—wincing with every pull against his head. He'll itch to tell him that he's being too forceful and he'll want to clarify that there's no need to pull so hard either—but he'll just exhale and wait for the soap to run through the strands. He'll twitch and think about how unsettlingly skittish he's being. The clumsy fingers—trying to be kind and partake of an intimate experience—will place him at an intersection between feeling like he'll look ridiculously weak and feeling agitated.
"Are you sure?" The pale-haired boy will ask, before leaning close and breathing against the other's ear. "Because I know you're just biting your tongue while I pull all your hair out."
"Wha…" He'll stammer—turning his head with a swift motion. "What do you mean you…You've been doing that on purpose?"
"I've been trying to see how long it'll take for you to make some noise about it. I think it's cute that you'd let me just yank on your hair, instead of telling me to stop," Allen will smile, fingering the edges of Kanda's hair lightly.
Kanda's shoulder will tremor and he'll make an irritable face before he'll push the younger partner away—standing up with a tick in his nerves. "You little shitface. See if I let you have stupid moments like this again!"
Allen'll just laugh, even as Kanda will stomp across the bathhouse—putting distance between them. He'll come back sooner than later and Allen will pick up where he left off.
A/N: I wanted to experiment and see if I could write in future tense. It's a little strange.