Also, very important: Asthma can impact a person's sex life. Since I'm taking part in Kinktober 2018 to get back into writing smut, I have elected to ignore Riku's asthma for the most part. However, if you have asthma, please be careful when engaging in sexual activities and make sure your partner is fully aware of it.


Please


Harsh, ragged breathing echoed throughout the room accompanied by the occasional groan. Discarded clothes were spread all over the room. Sheets crumbled and soaked with sweat beneath two bodies, the mattress dipping with each movement.
"Please, more", Riku moaned clenching around the fingers inside him. Fingers travelled down his spine at a leisure pace and a light kiss was placed on his right shoulder blade. He had no idea how long this had been going on except that it had been long enough for his body to become unable to support itself. His hips were propped up with a couple of pillows to give the illusion of being on his knees, his upper body pressed flush against the bed sheets.
"Patience. I'll give you what you want soon enough", Gaku purred into his ear pumping his fingers in and out of Riku at agonizingly slow pace. Leaning over Riku's right backside bracing himself next to Riku's head with his free hand made it easy to nip at Riku's neck.
Riku whined biting down on the sheets. His hips bucked to meet Gaku's fingers and to gain some friction from the pillows beneath him. A low moan escaped Riku when Gaku's fingers brushed against his prostate. But it wasn't enough. He needed Gaku to fill him up, stretch him, make him feel full.
"Please, just, please, fuck me", Riku rasped, his body quivering, his mind beginning to feel hazy. Gaku groaned. He loved teasing his lover, seeing him fall apart under the pleasure. What he loved even more was Riku begging for him, needing him.
Gaku bit down a little harsher on Riku's neck eliciting a gasp from the younger man. Burying his fingers deep inside Riku one more time before pulling them out, he sat on his hunches. Riku groaned his disappointment at the loss, while Gaku reached for the bottle of lube he had discarded earlier.

Gaku positioned himself between Riku's spread legs. Pulling Riku's left butt cheek to the side with the hand that had been buried in said ass earlier, he let the tip of his cock poke against his lover's twitching hole. Riku's hips lurched backwards in an attempt to get Gaku's cock to slip into him.
A warning growl and a slap to his ass from Gaku had him still in an instant. Gaku rocked his hips back and forth dragging the tip of his cock over Riku's hole again and again using his hand to keep Riku's hips from moving to much.
The lube bottle opened with a pop. Gaku poured the lube over his cock and Riku's ass crack smearing it over Riku's hole with his cock. He discarded the bottle again. The hand on Riku's lower back moved lower and spread his butt cheeks apart. With his thumb, Gaku applied light pressure to Riku's hole without breaching the barrier sending jolts up his lover's spine. His other hand pumped his own cock to spread the lube around his cock.
The sight of Riku's twitching hole and spread legs was a vision from heaven. Even more so with Riku on his knees, hips kept up only by pillows. The mewls and moans were music to Gaku's ear as much as Riku's singing. It made him want to keep Riku all to himself and lock him up in his bedroom.
When Gaku was satisfied that he cock was lubed up enough, he gripped Riku's hips tight enough to prevent any movement, but not enough to leave bruises yet. He lined himself up with Riku's hole. A needy moan escaped Riku. Then Gaku pushed in, millimetre by millimetre until his head popped inside.
"Fuck me, please. I need you to fill me up, stretch me", Riku begged moaning in the obscenest way he could manage. Gaku leaned down with a growl nipping and sucking at Riku's shoulder blades. Then he began pushing in further. The stretch felt so good. Riku loved the slight burn that came with it, three fingers never managing to prepare him enough. But that was okay. Riku craved that feeling of suddenly being too full.
When Gaku was halfway in, he snapped his hips forward burying himself to the base in one powerful thrust. Riku screamed clawing at the bed sheets, clenching around the cock seated deep within him eliciting a delicious mean from his lover. Gaku's cock was stretching him to the limit just like he loved it.
"Is this what you wanted?" Gaku purred, dark and sinful. His grip on Riku's hips tightened in order to keep himself from thrusting with abandon. He wanted to draw this out. After all, he still had something planned. It would be a shame if it ended before he could act on it after all the discussing they had done.
"Yes, yes, yes", Riku sobbed overwhelmed by the pleasure of being filled. Gaku began rocking into Riku at a relaxed pace never pulling out more than two fingers' width. His right hand left Riku's hips to reach up to his face. Taking hold of his lover's chin, he leaned down pressing his chest flush against the sweaty back. Gaku forced Riku's face to turn left claiming his lips in a hungry kiss.
Tongues danced with each other, breaths mingled. Lips moved against each other with greed. Each time Gaku's undulating hips caused Riku's erection to rub into pillows., the redhead moaned into the kiss. When they broke apart, both were feeling hazy and heady.
"Fuck me harder, please. Make me feel it tomorrow", Riku pleaded in a needy way pressing himself back against Gaku.
"Not yet", Gaku murmured licking Riku's lower lip. Riku whined and wriggled. Gaku clenched down on Riku's hips with both hands, hard enough that bruises were beginning to form. It did the job of keeping Riku frozen in place.
Gaku continued with that agonizing, slow pace. From time to time he would rake his nails across Riku's back leaving thin, red lines behind. Whenever, Riku would clench down on his cock, Gaku would stop moving drawing out high-pitched whines from the redhead.
The game continued until Gaku felt pressure building up in his abdomen. His thrusts became longer, more powerful as the pressure in his bladder continued building, chest sliding against Riku's back. He held back as long as he could. When he felt himself reach the limit, he buried himself inside Riku with one forceful snap of his hips. The moment, he couldn't hold it anymore he bit down on Riku's neck hard enough to draw a few droplets of blood.

The combined feeling of being bitten and having his ass filled with warm urine had Riku screaming in pleasure pushing him over the edge. His body rippled with shockwaves of pleasure, his vision whitening out for an instant. Cum shot from his cock soaking the pillow and his skin.
When Riku came back to himself, his body had gone limp and he could still feel Gaku going on, the urine starting to leak out of his ass. Drool was dripping from the corner of his mouth. He felt Gaku dislodge his teeth and lick the mark a couple of times.
"I'm going to fuck my piss deep into you mixing it with my cum until you're so full you'll feel it for days", Gaku growled into Riku's ear. It was only then that Riku realised that Gaku was still hard. Riku made a keening, pleading noise, not capable of doing much more.
The response was immediate. Gaku pulled out almost completely before thrusting back in setting a brutal pace. Every single thrust was a straight hit to Riku's prostate. Being still too sensitive from his orgasm caused the jolts running through Riku's body to be of painful pleasure.
The screams of pleasure and pain seemed to spurt Gaku on even more, the brutal pacing increasing until his hips began to stutter and the thrusts became irregular. Several more thrusts and Gaku stilled once again deep inside him. The knowledge of Gaku's come and piss mixing inside is ass had his cock twitch in interest despite the painful pleasure.
Gaku's strength seemed to leave him as he collapsed on top of Riku pinning him down. Riku could feel Gaku's body quivering and lurching, hear him moan into his ear while he rode out his orgasm. Riku felt like his abdomen was full enough for it to show.

Once Gaku's orgasm had subsided, he blindly felt for the desired object while lifting himself off Riku with his other hand. Finding what he had been looking for, he pulled out and replaced his cock with a butt plug to keep the cum-piss mixture trapped in Riku's hole.
Then he dropped onto the mattress next to Riku and pulled the redhead, whose quivering had yet to stop, with him. They came to lie on their side as Gaku slung an arm around Riku's waist. With a gentle hand, he rubbed Riku's abdomen murmuring sweet nothings into Riku's ear.
"How do you feel", Gaku asked nuzzling Riku's neck. The response was nothing more than a satisfied hum from Riku.
"You aren't in any pain?" the silver-haired idol hedged knowing he had been a bit rougher than what was normal for them.
"Only the good kind", Riku yawned. It was apparent that their session had tired him out. Gaku gave him a short sweet kiss.
"Thank you. I'll clean you up", Gaku replied getting up and lifting Riku into his arms. It took a bit of time to manoeuvre out of bed, but he managed.
"I liked it, too", Riku mumbled half-asleep. A fond smile made its way onto Gaku's lips as he walked towards the bathroom. Sometimes, he wondered how he ended up so lucky. Gaku made sure to be careful with Riku while he washed them both in the bath.
Afterwards, he didn't bother dressing either of them since it was warm enough. Instead, he wrapped Riku into a warm, fluffy towel and deposited him on the armchair while he changed the sheets. After he was done, he removed the towel dropping it on the floor and then tucked Riku into bed with him. It didn't take long until they succumbed to blissful sleep.


I actually researched whether it's possible to pee while being aroused with a penis and it apparently really depends on the individual. Some can do it easily while others have a hellish time attempting it.