Warnings/Notes: slash, alternate universe - modern setting, one-sided crush, jealously, blowjobs, underage sexual activity.
Riku did not mind...at first. Tidus was one of Sora's best friends. Riku was perfectly fine with letting Sora hang out with Tidus, because - honestly - he never thought of it as a problem. Sometimes he would even go along with Sora whenever Tidus wanted to meet up. As far as Riku was concerned, Tidus was a pretty all right guy.
Although, noticing certain signs when with Tidus didn't take long at all.
It started on a Wednesday after school. Normally, Riku would drive Sora home since they lived on the same street (and because Sora hated being on the bus at the end of a school day; he still wasn't old enough to drive on his own), but Sora wanted ice cream and Tidus was naturally invited along. And Riku was okay with that. Luckily for him, there was a little building that sold ice cream, among other things, not far from their street so it wasn't completely out of the way.
Riku ended up paying for both his and Sora's cones. Sora almost never carried any money with him, the only exceptions being for school lunch and the occasional video game. After over one year into their relationship, Riku was more than used to paying for Sora's food. And ordering Sora's food for him. Riku left Tidus to buy whatever he wanted and sat next to Sora at one of wooden tables with benches for seats near the building.
Sora reached for his ice cream first and Riku second, wrapping an arm around Riku's back once he had the treat in hand, his other hand settling on Riku's hip. Tidus walked over, carton of fries in hand, and playfully threw one at Sora, which was met with a squawk and no attempt to dodge, before sitting at the other side of the table. Riku chuckled behind his ice cream and said nothing while Sora sat with a fry in his lap, not even willing to shake his leg to dislodge it. He just inched himself a little closer to Riku and pretended it never happened.
The weather was warming up again, and Sora was excited about summer vacation coming in a few months. Happily talking about it with Tidus, Sora licked leisurely at the vanilla ice cream in his cone. Sora's index finger went up under Riku's shirt a little, touching skin, and Riku could say he was having a good time.
That was, of course, before he saw what was going on.
Tidus was looking at Sora. Which shouldn't have been a big deal since they were talking and Tidus wasn't one to avoid eye contact. However, Tidus was sneaking glances at Sora's mouth, particularly when it was preoccupied with ice cream. Slightly bewildered and a little angry, Riku wasn't sure what to do.
Sora chatted away, none the wiser, and stole one of Tidus's fries.
Later when all the food was eaten, Riku and Sora parted ways with Tidus, who chose to walk home instead of hitching another ride from Riku. Riku's fingers gripped the steering wheel a bit harder during the drive to Sora's, but he refused to get ahead of himself and jump to conclusions. There was probably no way Tidus was actually staring at Sora in that way. Riku knew better than to start getting jealous, especially if it really did turn out to be nothing. And, besides, Sora was with him, not Tidus. Pacified with that reassurance, he slowly pulled into the driveway at Sora's house.
Walking Sora to the door and kissing him goodbye, Riku went home.
After that day, Riku began to notice other things about Tidus whenever Sora was around. Like how he sometimes looked at Sora a bit longer than he should have, only a couple seconds that might as well have been minutes. Or like how there were times when he would hand Sora something and their fingers would brush because Tidus did it on purpose. And how could Riku not see the way Tidus got tense every single time Sora became affectionate with Riku in public.
Three weeks of Riku watching Tidus passed, and Riku was a mentally brooding balloon of jealously ready to pop.
"Are you okay?" Sora asked, pausing his game to look at Riku.
It was Saturday afternoon, which usually meant an all day video game marathon for Sora with Riku over just sitting around. Sora wore a concerned expression from his place on the floor at the foot of the bed.
"I'm fine," Riku answered. He was laid back on Sora's bed, eyes aimed at the ceiling. "What's up?"
"It's just," Sora began, controller forgotten. "You seem kinda upset lately." He got up from the carpeted floor and sat next to Riku's feet. "You wanna talk about it?"
Riku leaned up on his hands. "Not really."
Fiddling with his fingers, Sora asked, "Are you sure?"
"Yeah." Riku scooted down the bed until he was sitting next to Sora. "I'm fine, promise."
"Okay," Sora said dubiously. He kissed Riku regardless, a simple three second press of lips. "If you say so."
"Don't worry, I'll let you know if anything changes," Riku spoke softly, leaning in for another kiss.
Sora made a sound of acceptance as their lips met again, resting his hands on Riku's upper arms. Riku clutched the fabric of Sora's shirt at the abdomen, slipping a bit of his tongue between Sora's lips for a second, just barely coming into contact with Sora's own tongue before pulling back. Huffing a breath against Riku's mouth, Sora kissed him insistently, trying to get Riku's tongue into play with a tease of his own.
A laugh bubbled up from Riku's throat, and he obliged by lazily sticking his tongue in Sora's mouth, receiving a pleased noise in response. Minutes passed, Riku's hand gradually loosening its hold in the shirt. Finally he let go completely then slipped his hand inbetween Sora's legs. Sora jerked slightly then relaxed.
Riku rubbed over him one time, Sora only just beginning to get hard.
They pulled apart, and Riku didn't waste any time sinking to the floor, resting his weight on his knees. Sora panted lightly above him, spreading his legs and leaning back a little, hands bracing him. Riku had the button of Sora's jeans undone and zipper unzipped before Sora was even properly settled. Red underwear separated him from Sora's steadily hardening dick, but Riku - with some help from Sora - slid Sora's jeans and underwear down enough so he could reach in and pull it out, the underwear left covering Sora's balls.
Fingers loosely curled around the base, Riku leaned in and flicked his tongue just below the head. Sora keened and squirmed.
Grazing his lips further up the head until he reached the slit, Riku opened his mouth to take Sora inside. Riku could only count on one hand how many times he's done this to Sora, but he was slowly getting used to the taste of flesh in his mouth. A shudder went up his back.
Tidus would never know the feeling of doing this Sora, not if he could help it.
His head dipped lower, taking more of Sora in. Sora grew harder against his tongue, and it wasn't long before a little precum leaked out only to be licked away by Riku, Sora shuddering at the wet organ touching his slit. Hollowing his cheeks, Riku set a slow rhythm with his head, his mouth sliding up and down Sora's cock.
Sora whimpered. "Riku..." His right hand went to the back of Riku's head while the left curled up into his bedsheets. Throbbing in Riku's mouth, Sora groaned, fingers twitching in Riku's hair.
"I love you," Sora moaned out lowly.
Riku blew a sigh out his nose and moved up off Sora's erection, his breath ghosting over the head. His lips felt really wet, the taste of precum spread over his tongue. Kissing at the slit, he took Sora back in, feeling happy and satisfied despite how his own dick remained pulsing hard in his underwear.
More precum dribbled out onto Riku's tongue, and soon Sora was coming down his throat whilst gasping. Sora fell back onto the bed, breathing hard as Riku swallowed around him. Riku stroked under Sora's shirt, pushing it up, and pulled his mouth off Sora's slowly softening flesh. He climbed up from the floor to straddle Sora's thighs, looking as his red face as he recovered.
Sora started to reach for Riku, still panting, but Riku shook his head quickly, undoing his own pants and barely getting himself out and stroking a few times before he ended up streaking come over Sora's uncovered stomach.
And the next day, if Riku felt at all smug around Tidus, he kept it to himself.
I haven't written any kind of smut in so long. This is probably really dumb. And really late. I apologise for that.