Prompt: Red/Charizard; Something involving Charizard's tail.
Even before the sex, the room had been stiflingly hot. Just being anywhere in close contact with the great lizard was enough to make anybody break into a sweat; heat radiated from the very scales covering its body, increasing in intensity near its soft underbelly and throat, where internal flame sacs were constantly broiling. Then there was, of course, the tail: the tip burning at temperatures that would leave at least second-degree burns on any flesh that so much as touched it, yet it did nothing to harm the beast itself.
Red had to be careful when he thrust into the Pokemon. The lizard would writhe beneath him, razor-sharp teeth exposed with each roar of pleasureful protest, claws digging into the charred mattress beneath its bulk. Deadly as tooth and claw could be, Red did not fear them; Charizard maintained enough control during these moments not to pierce his master's fragile skin. No, it was the tail that was the true threat. Even though he kept his sweat-slicked arms wrapped tightly around the appendage as he worked, he could feel the muscles flexing violently, begging for release. He had watched Charizard mating rituals before, before deciding to take part in them himself; the tails would thrash-- almost chaotically, until one noticed that they were synchronized in a feral dance-- and the flame would grow until the pair's image shimmered in the hot air, seeming almost like a mirage.
The memory flooded into Red's mind: the beauty of their incandescent dance, the desire to be a part of that passion... His own passion flared for a moment and he spilled himself into Charizard, letting out a low groan that sounded weak and feeble in comparison to the dragon's contented growl in response. Red's own sweat had coated the lizard's scales, which now shone beautifully with reflected light. Breathing heavily, Red ran his fingertips down the smooth backside, moving as far down the burning tail as his self-preservation instinct would permit.
Red straddled the base of the tail, gently rubbing his naked thighs against it. He could feel Charizard's muscles twitching in response, and he pressed the rest of his body against the tail. As he stared into the blaze, he felt his own warmth return. He was ready for another round.