Notes

A mischievous visiting mage switches Makarov's outfit out with a skin-tight spandex outfit. Naturally, he gets held down and fucked by Natsu and Grey.

One second, he had been enjoying one of Mirajane's drinks, his cheeks tinted with a slight red.
The next, he felt something alike to his body tightening, and, absently, he glanced down. His blush intensified as he realized he was no longer wearing his respectable mage's outfit, but instead a tiny little spandex outfit that seemed custom-designed to fit his diminutive stature and highlight his well-defined, chiseled muscles.
Never one to stay frozen, Makarov immediately leapt down from the counter and rushed through the back door, praying only that no one had seen him in this rather embarrassing outfit.
He burst through the next door into the open, and immediately regretted it as he realized he was in a very public, crowded area. Almost as if by some magic cause, it seemed everyone was suddenly inclined to look at him, and as they did, their eyes trailing over his muscular build that stood in stark contrast to his small size, leers simultaneously grew on their faces. Makarov stared at the ground as he rushed through the crowd, but, as panicked as he was, he didn't notice as his foot tripped on a suspiciously raised stone. He fell hard, his body reeling from the impact.
Makarov was just about to pick himself up when he felt a much larger body press itself against him, forcing him onto the ground and grinding against the entirety of his body. Makarov's entire face grew red as he struggled to escape.
"And what do you think you're doing out here in that skimpy outfit, little dude?" The stranger whispered lustily into Makarov's ear. One of his hands slid up his well-built chest and started teasing a little nipple, forcing breathy moans out of Makarov.
"Fuck, that's cute," the stranger said, his other hand now moving to fondle his ass. Makarov felt only more embarrassed as he was easily maneuvered onto the stranger's lap as if he were a small child.
"P-Please don't," Makarov managed to stammer out. He hadn't even considered using his substantial magic abilities - even when they were very obviously violating him and on the verge of raping him, he was still completely unable to harm a civilian.
"And why not?" The stranger asked. "You couldn't possibly have come out here in that and expected no one to not push you down and have their way with you."
"I-I didn't put this outfit on," Makarov responded shyly. "I just suddenly was wearing it. Please-"
He cut himself off with a deep moan as the stranger slid his hand down and squeezed his hardening cock mercilessly.
"You like that, little dude?" asked the stranger condescendingly. "You like it when I play with your tiny cock?"
Makarov shook his head desperately.
"Don't lie to me, you fucking slut," the stranger hissed into his ear. "Old men like you should just lie down and take it."
Makarov felt like crying. He hadn't felt that way for a very long time. The stranger halted abruptly, and Makarov prayed that he had come to his senses, but instead, the stranger shoved Makarov closer and whispered, "shit, have you even been laid yet?"
Makarov froze. In the technical sense, he had had sex, he supposed, in that he had produced offspring, only it was less sex and more forced sperm extraction. The experience had turned him off quite a lot, and he had never sought out a sexual partner since.
Though Makarov was sure he hadn't said any of this out loud, the stranger still gave a chuckle, tweaked a nipple, and said, "you're what, 70? And you haven't even been fucked yet? Jesus."
Makarov only shivered, his blush remaining as ever on his face. He felt the stranger beginning to peel the outfit off of him, and was almost about to resign himself to his fate, when he heard a strong, clear voice yelling.
"Stop that, you jerk!" the boy - Natsu - shouted furiously. The stranger turned around with an annoyed look on his face, and then his expression was suddenly obscured by a boot that planted firmly into his head and sent him flying into a brick wall.
Makarov, feeling nothing now but relief, looked over in awe at Grey, who had just kicked the stranger hard enough to, perhaps, kill him.
The black-haired teenager looked around disapprovingly, his expression morphing into one of rage as he yelled at the crowd, "what the hell are you looking at!? If you so much as glance at our Master again, we'll kill you!"
The crowd immediately dispersed, leaving a wide area in which only Grey, Natsu, and Makarov resided.
Makarov immediately felt another cold wave of shame wash over him. He was supposed to be the Guild Master and one of the Ten Wizard Saints, and yet he was so weak and feeble he hadn't even been able to stop some pedestrian from forcing him down and taking his virginity.
"Th-Thank you, you two," he said quietly.
"No thanks needed," Grey replied coolly. "Guys like that need to be put into the ground."
Makarov almost scolded Grey before remembering that he had just saved his dignity and most likely his sanity, and refrained from saying anything.
"Anyhow," Natsu said, a grin forming on his face, "where were you going? We can take you there."
Makarov felt an unsteady smile form on his face. "I was going to my apartment, actually."
"You have an apartment?" Grey asked.
"Well, I don't go there too often, but yes, I have one," Makarov said, feeling now much more calm now that Natsu and Grey were with him. "Let's go then."
And so they walked to his house, Natsu and Grey on either side of him, giving menacing glares to anyone who leered or stared at Makarov.
By the time they reached his apartment, Makarov was feeling quite happy, all things considered. He let the boys in, and then rushed to his closet to change into something more appropriate.
He tore the spandex off, momentarily leaving himself naked, but as he reached out to grab a collared shirt, he froze at Grey's voice.
"I thought he was hot with the spandex," Grey said, "but he looks even sexier naked."
Makarov felt the blush immediately rush back to his face, and he instinctively jumped into the closet, the door sliding closed until a hand forced it back open with overwhelming strength - Natsu.
"N-Natsu, Grey, what are you two doing here?" Makarov shouted, trying to sound stern but, as he realized, sounding only fearful and anxious.
Natsu stepped back to admire the well-muscled, cowering form, saying only, "just admiring the view."
"Hey now," Grey said with a smirk, approaching slowly, "we don't just have to look." With one swift movement, he grabbed Makarov by the hips and pulled him up. "We can touch too."
Makarov shivered despite the warm temperature in his apartment. "What is the meaning of this?" He asked with no gravitas.
Natsu shook his head. "You were jumped on the street, Master. Do you still not realize how hot you are? How fuckable and sexy you are? Obviously, once we got you alone, the only thing we could do was fuck you."
Makarov groaned helplessly as Grey rubbed his hand against one miniscule, muscled pectoral, his hands flailing by his sides to no avail.
Grey threw him carelessly onto the bed, then jumped onto it and held Makarov's arms down. Makarov now considered using magic, but as he looked up at the face of Grey, and at Natsu, he felt himself soften. Despite what they were doing right now, he still saw them as his children. He couldn't simply attack them.
Grey and Natsu, perhaps aware of this and perfectly ok with exploiting it, only lay on either side of him on the bed and began teasing his nipples, cock, and ass with frightening speed.
Makarov's moans seemed constant and never-ending, and within a few seconds, his cock was spurting violently, come spewing out with a force and in a volume completely disproportional to his size. He could feel his cock clenching violently, his entire body twitching uncontrollably as the pleasure completely took him.
"Some of it even landed on the ceiling," Grey said with a sneer. "What a slut we've got, eh, Natsu?"
Natsu nodded his head maliciously. "Yeah, that's right. And sluts need to be fucked and violated, don't they?"
Makarov tried to scramble away, but his arms were still pinned. Instead, he begged, "please, Natsu, Grey! This is wrong. Just let me go, and we can forget that this ever happened. Ok?"
"How cruel, Master," Grey cooed mockingly. "To deprive us of your body like that? You must not care about us."
Makarov felt a flicker of anger within him, but it was quickly extinguished by a flood of shame as Natsu tucked one finger into his petite ass.
"We've wanted to do this for ages," Natsu said shamelessly. "Just press you down and take whatever we want from you. And when we saw you suddenly in that outfit - well, we couldn't help ourselves. How could anyone?"
Makarov attempted to shield his face with the pillow, but Grey gently pulled it back and forced him to stare, with glimmering eyes, at his two children in all but blood. His body, rippling with muscle, was now splattered in come everywhere, his face half-lidded and smeared in his own semen.
"A-ah," he grunted out as Natsu thrust another finger into him.
"We don't want to hurt you," Natsu said rather ironically. "We're not going to stick our dicks into you until we find a way to force you to stay in one of your larger forms, so, for now, we'll just finger-fuck you."
"How nice of us, eh, Master?" Grey asked harshly, his hands still on Makarov's cheek.
Makarov only silently glared at Grey. Grey responded by trailing a hand down his chiseled chest and pinching a nipple at the same time that Natsu thrust both fingers against his small prostate. Despite his age, he still thrust up and screamed hoarsely as another orgasm rushed through him and left him almost unconscious.
When he recovered, Grey repeated this question. This time, with a trembling voice, he muttered, "thank you."
Natsu thrust the two fingers roughly into his prostate once more. Makarov's eyes rolled up into his skull as he roared in pleasure.
"Thank you for what?" Grey asked, his hand moving to tease Makarov's perked, pink nipples.
"D-don't, please," Makarov begged with a pink face. "Please don't make me say it."
Grey looked at him without a hint of compassion. As Natsu began to roughly thrust his fingers in and out of Makarov, so hard that the old man's muscled body was raggedly thrown back and forth with the motion, Grey bent down and sucked Makarov's tiny cock into his mouth. The Guild Master sobbed out his pleasure as he came once more.
"Thank you for what?" Grey repeated once Makarov finally stopped, his body collapsing onto Natsu's still thrusting hands in a sweaty heap.
"Th-thank-" he interrupted himself with a loud sob as Natsu began fondling his prostate with his hands, the pleasure sharply shooting throughout his entire body.
"Come on," Grey goaded meanly, "I get that you're old, but you can't be so useless you can't even thank us for being so gracious."
"Thank you," Makarov whispered, his body flung up and tugged back down with Natsu's rough motions. His voice was broken, his body limp. "Thank you for only finger-fucking me."
"That's right," Grey said victoriously. "We're quite the good masters, aren't we, Master?" He snickered quietly.
"Yes," he sobbed as Natsu continued to assault his prostate without mercy. "Yes, yes, yes, yes, yes-"
He arched his back to a near-impossible angle as he came for the third time in that hour, his mouth opening and his cock spasming as the come shot in every direction - onto Grey and Natsu's naked bodies, onto his white mustache and hair, onto his sculpted abs and pectorals, the bed posts, everywhere, it seemed. Natsu had finally given him a temporary break, and Makarov collapsed onto his unmoving hand with harried pants.
"Ngh," he gritted out as Grey's hand returned to teasing his nipples. "AH!" He yelped as Natsu pulled out of his ass completely and thrust back in.
"He's completely loose now," Natsu complained, though he continued to finger-fuck Makarov roughly.
"It's fine," Grey replied calmly. "We need to research a way to force him to use a litle bit of Giant magic anyhow. I want to see," he said with a sneer, "how the old geezer looks with come leaking out of his ass."
Natsu grinned and finally pulled his fingers out, rushing out of the room with a shout about returning to the guild to ask people for help. Makarov felt his horror somehow intensify further at the thought that his precious guild members would discover his predicament. Grey looked at Makarov, then slid his hand down to his cock and begin aggressively stroking the old, broken, tiny man.
"Come," Grey commanded. "Come like the useless old man you are. This is the only thing you're good for. At the very least, old geezers like you should know how to come right."
Makarov screamed hoarsely as, as Grey said, he came again. As Grey rose from the bed, he took out a pair of handcuffs from underneath his clothes and locked him to the bedpost, finally departing from the bedroom with a slap on the ass that made Makarov squeal embarrassingly.
"Slut," he said as he walked out.