Superboy likes the sounds Robin makes. He likes listening to the boy pant when he trains three rooms away, he likes when he sighs at Kid Flash's comments to M'gann, he likes the groans and growls of annoyance when something doesn't go quite as planned, he likes the almost creepy giggle that echoes around them all in battle, and he likes when he talks (even if he doesn't always understand what he's saying).

Superboy likes the sounds Robin makes so much that even when the static of No Signal has his full attention, he's always listening for any noises coming from the boy hanging around the base. Sometimes it means M'gann has to repeat herself several times for Superboy to notice, but it's worth the exasperated look he gets from her.

Right now, Robin is working out in the weight room. Superboy can hear the clink of iron against iron and the creak of hard cushions crumpled by a small body. He's 95.682 percent sure Robin is bench pressing and from the sound the bar makes when Robin rests between sets, he's 72.43 percent sure it's 175 pounds. It isn't much, but Robin is small and young and doesn't have super-strength like Superboy so it's okay. Superboy stops paying attention to the sounds of the weights and focuses instead on Robin and how he breathes. His breaths are long and deep, carefully in time with his lifting and lowering of the bar. After a while, they get shakier, and shorter, and Robin starts making a sound somewhere between a grunt and a whine. After a full set of this, Superboy shifts in his spot on the couch. He's grateful when Robin moves on to a different exercise, his breathing once again rhythmic and slow, but for some reason, he's also disappointed.

They're in the middle of a mission and even through his own grunts of exertion and the impact of his punches, Superboy can hear Robin. He's twenty-eight feet away and surrounded by six of the bad guys. He listens to the sound of Robin's boot smashing into the face of one of the guys, the squeak of his glove as it curls into a fist, the flap of his cape as he jumps, and the grunts escaping from his mouth. Superboy is concentrating really hard on throwing the guy in front of him into a wall, but Robin is so distracting.

When that laugh comes from nowhere and everywhere at all, he hesitates. It makes his stomach feel tight (it messes with his sound localization, he tells himself) and then suddenly his stomach feels funny not because of that laugh but because of the fist currently buried somewhere between his ribcage and where he learned his bellybutton should be. He roars in anger, ashamed at having been caught off guard, and lifts the guy over his head. Superboy's about to chuck him through the window when he hears a quieter version of that laugh next to him.

"Easy there, Supey, they're just drug dealers."

Scowling, he tosses the guy to the ground (lightly) and manages to catch Robin's snicker over the thud of the body against the floor.

Superboy is seated at the kitchen table, watching Robin stretch to reach something on the top shelf of the cabinet. He wonders why the boy doesn't do one of his flips or jumps and figures it's a matter of pride. Everyone else on the team can reach the top shelves just fine.

Robin squeaks when Superboy lifts him by the waist to hold him face-to-face with the can of soup he was aiming for. Superboy's lips twitch upwards as Robin's head turns to glare at him, angry eyebrows visible just above the sunglasses. "I'm not a little kid, Supey," he tells him, scooping the can off the shelf before wriggling out of Superboy's grasp and landing lightly on the floor.

"You are little," he replies, watching as Robin prepares the soup. At Superboy's words, he huffs, and Superboy thinks it's...he thinks "cute" is the right word. He feels like how M'gann looks when she sees a puppy on the television. He doesn't really know why, but he's smiling (just a little) and when Robin turns around from the stove, he smiles back at him.

Robin is sleeping at the base tonight, for some reason. They didn't have a mission today and he didn't know Batman gave him nights off, but he thinks schools are closed for the week so it must be a special occasion. Or maybe Robin is just really good at convincing Batman.

Superboy wakes up at some point during the night. He isn't sure what woke him up until he hears Robin. His teammate sleeps in the room two down from his and though he isn't anywhere near loud enough for M'gann to even hear him, the noise wakes up Superboy. After a few moments of confusion, his mind flashes back to something he caught Kid Flash watching on his laptop one day. It involved slippery naked people that made noises like the ones Robin is making now.

Only Robin doesn't sound like the people in Kid Flash's video. He isn't growling and cursing like the man or screaming and moaning like the woman. Instead, he sounds like the quiet median of the two; his breathing is shallow and jagged, and he's moaning, but the moans are shorter and softer than the woman's. As he listens, Superboy feels something throb in between his legs. He tries to ignore it, but as the minutes pass and Robin gets louder and all Superboy can hear is gasping and moaning and the pounding of Robin's heart and the slide of skin against skin, he can't ignore it.

When Robin lets out a strangled gasp, he thinks it's finally over, but after two long, quiet minutes of Superboy trying to ignore the throbbing in his blue and red boxers, Robin starts again. As Superboy glares at the ceiling and shoves his hand angrily into his boxers to do something, he thinks maybe this is why Robin slept here instead of at Batman's house.

They're kissing. Superboy has no idea how it happened, but it's been happening for a while now. He would think Robin has no idea how it happened either, but Robin always knows. They're on Superboy's bed and Robin is almost weightless on top of him and when Superboy thinks about the sounds Robin made that night, he kisses him harder. Robin makes a humming noise in his throat and Superboy really likes it.

At some point, Robin starts gasping and not-quite-moaning, and now that Superboy thinks about it, it's probably around the time he starts sucking at his neck. He would be worried that Robin's in pain, but it sounds more like That Night than any of their missions, so Superboy continues.

Suddenly, Robin is pushing him off and Superboy is frowning, but Robin is panting out words, so he listens. "Look, I know you don't bruise, but I do, and having to explain hickeys to Batman would be totally disasterous."

Superboy has no idea what a hickey is, but the idea of explaining anything about this to Batman is more than a little terrifying, so he listens quietly as Robin puts his cape back on and heads softly to his room.