[Spoilers for post-Silver Soul Arc, don't read if you're not caught up]
This idea popped into my head a while back when thinking about Yamazaki's mayo bottle dick. I apologize in advance. Rated M for suggestiveness, not smut.
Set after Yamazaki regained his memories, but don't think too hard about it timeline-wise.
Note: I *think* Hijikata had still quit smoking after the timeskip? I don't completely remember, so if I messed up any details, let me know.
Working on reports late at night had sucked ass when Hijikata was in the Shinsengumi, and it sucked just as much when he was with a regular police force. It would always suck: that much wouldn't change any time soon.
His hand was getting twitchy, itching to light up a cigarette even though he'd quit two years ago. Fine, so he couldn't smoke, but Hijikata had another favoured vice in his life, and it was probably around time to give himself a little break. Just a small one. He'd slurp the mayo out of the bottle in a few seconds flat and fuel himself for the rest of the night.
Hijikata reached into his sleeve, but it was empty. Shit, that was right- he'd used that one already hours earlier.
Pat, pat, pat. Damn it! None tucked away inside his collar, either!
"Oi, Yamazaki." Hijikata turned to the corner of the room that the incessant whirring made impossible to ignore. "Go and get me some mayo, will you? I'm out."
Yamazaki's head made a metallic screech as it turned, his hand still continuing to write his report. "I'm afraid I can't, Hijikata-san. All nearby shops are currently closed at this hour. The nearest 24-hour convenience store is in Edo."
"You can fly, can't you?"
"The journey would take an estimated five hours. I am also likely to run out of fuel in that time." Yamazaki paused, before adding, "The closest shop to this area will open in three hours. If you would still like me to-"
"Don't bother. If I have to wait that long I'll go into withdrawals," Hijikata cut him off and snapped, pacing back and forth in thought. He soon stopped, facing the corner of the room again and folding his arms in resignation.
"Hijikata-san?"
"Tch, I have no choice. Yamazaki, get it out!"
Yamazaki only blinked. "Huh? Get what-"
"Your ****! Whip it out!" Hijikata demanded. "You have one, right? A mayo bottle in your crotch!"
"Uh." Despite being a cyborg, Yamazaki's face paled. "Well, yes, but-"
"What's the matter? You had no problem doing it before. Don't make me ask you again!"
"O...OK." Eventually, Yamazaki complied, turning around in his chair to face Hijikata, the compartment in his crotch opening up and revealing the mayo bottle just like when he'd used it on the katsudon. He swallowed nervously, managing to keep his doubts to himself as Hijikata dropped to his knees.
Looking up at him from between his legs, Hijikata took the nozzle in one hand, holding onto a metallic thigh with the other.
"Yamazaki... Don't tell anyone about this."
Before Yamazaki could have anything resembling second thoughts Hijikata was already going at him like a Mayora possessed, sucking out the mayo with the force and speed of a vacuum. He looked like a fish with that nightmare-inducing expression, bulging eyes and pursed lips—was this his true form? Hijikata-san's true form?!
"Hi-Hijikata-san!" Yamazaki practically squeaked, bent over and gripping the other's shoulders, "Too quick! That feels weird! Really weird, like I'll be sick! You'll suck it all out! The tama I don't have anymore and the tama I still have! You'll suck at least one of them out—!" his voice jittered with static as he cried out, his fingers leaving scorch marks from where they were clenched—"Aaaaahh-!"
"Ah... That was good." Hijikata wiped the creamy residue off his mouth when he was finished, licking it off his hand. "I feel so refreshed." He smiled as he stood up and returned to his desk, leaving Yamazaki slumped in his chair and ignoring the smoke rising from his body and the pure white of his rolled-back eyes, like his soul had vacated the premises.
"It was a little saltier than usual... A different brand, I wonder?"