A/N: Found this in my old story prompts; it's based off of one of those tumblr AU posts, the prompt being something like "Hi I was just walking by and saw you spray painting and it looks really good and would you mind showing me how?" And this is what it turned into...
I'm at Rocky Mountain Fur Con this weekend, just in case anyone is there and wants to say hi? I know these two fandoms probably don't overlap much but if you're there I'm the one with ears and a laptop! (I'm friendly I promise)
Robin was on his way home from a late night mission. Mumbo had chosen to break out of jail at close to two am and he was the only one awake enough to respond quickly to the scene and stop him. Apprehending the villain was easy enough, even in Robin's sleep deprived state, and soon he was walking sluggishly home, too tired to use his grappling hook. Before he knew it, he'd walked upon a teen, maybe a year or two older than him, spray painting a wall.
"That's pretty cool," Robin's sleep-addled brain supplied, and the teen flinched, seeing Robin's uniform in the dim light. He turned like he was going to run away, but Robin caught his wrist quickly.
"Hey, no need to be startled! That looks awesome!" And it did. The teen wasn't graffiting a penis or some other rude joke, he was painting something bright and swirling, blues and reds and yellows bleeding into each other. "You've got to show me how to do that!"
"Um, okay," the teen said, a little nervous. "Are you sure? You are Robin of the Teen Titans, I mean. This isn't really legal."
"Ah, forget about that!" the hero smiled. "This is too cool. I wanna see how it turns out!"
"Well, okay!" the teen said, starting to sound excited. He brushed a strand of choppy red hair away from his eyes, leaving a smear of yellow paint on his cheek. "I start like this… with the blue…" The teen showed Robin what he was doing before he was interrupted, and about an hour later, a gorgeous, swirling galaxy was painted on the wall in front them, spots of yellow and white looking like stars in the cloud-like spiral of blue and purple paint.
"And that's pretty much all there is to it," the teen smiled softly, and Robin blinked rapidly, like it was impossible that the teen had done all of this.
"That's…" he faltered, backing away from the art. "It's amazing! What's your name? I need to look out for you for when you're famous!"
The teen smiled back at the hero and shook his head dismissively. "Um..."
At that exact second, the wailing of police sirens cut through the air, along with red and blue lights flashing.
In a second, the vandalizing teen had launched himself into the air, scaling the wall and flipping himself up over the roof in a second. Robin blinked at the teen-shaped hole beside him before realizing he should probably do the same, taking only one second to smirk and grab the duffel of spray paints still sitting on the street beside him. He did have to return them, after all…
Two weeks later, Red X was throwing himself over a rooftop, trying to escape with a thick bag of delivery pizzas. He smirked as he thought he'd gotten a clean getaway when-
"Red X!" Robin's shout echoed through the air, attempting to catch up with the thief. Something heavy seemed to be weighing him down, however, and Red found himself slowing, if only to mock him a little.
"I think you forgot something," Robin continued, dropping the large duffle bag on the rooftop. Red X only had time to stare before the teen hero snatched the pizza bag back and continued on his way.