Prompt: When chilling in the ventilation system, Clint hears Bruce singing in his lab. He returns every day just to hear Bruce sing- and one day, Bruce sings directly to him.

Have I ever told you how much I ship Hulkeye? Have I? Well, now you know. This is, obviously a prompt (hey, did you know I take prompts? Message me, on Tumblr: 'wordsareagirlsbestfriend' or here. I try to fill them, even though it may take a week or two. It's fun, writing for people, I've found.) I had a little trouble with accidentally switching to past tense so if you see any mistakes... let me know.

Enjoy.

Clint loves the ventilation system in the mansion. It's big enough for him to fit easily, small enough to be comfortably and reassuringly snug, and it's so big he could spend days up there. Which he did, at one point, but Tony told him off. These days if he spends over an hour in the vents, Jarvis will tell the billionaire who will threaten the assassin until he entertains himself like a normal person.

Clint's in the vents above the labs when he hears it. At first he thinks it's his imagination, because his mind has certainly come up with weirder things, but as he continues crawling it gets louder and he realizes that somebody in the labs is singing.

There are only two people who spend time in the labs, Bruce and Tony, and singing like this (soft wordless, but beautiful if Clint's being honest) doesn't really seem like Tony's style… So Bruce then.

Curious, the assassin crawls up to grille closest and peeks into the lab.

Yep, it's Bruce. The scientist is staring at a screen in complete concentration and doesn't seem aware that he's singing. For some reason, this makes Clint smile, and he sits there, listening to that deep, soothing voice, before quietly crawling away.

He doesn't know why, but the next day he finds himself crawling back to the vents above the lab again. He sits there for a few minutes, no sure what he's waiting for, and Bruce starts singing, a slow and soft cover of some top forty hit.

Clint grins and sits there long after the song is over, waiting for a reprise, but he gets none so he crawls away.

He sits next to Bruce at dinner, and for some reason he finds himself unable to look him in the eye. He tries to act normal, but occasionally the scientist will say something and Clint will be distracted by his voice. He's never noticed how nice it is until now.

He misses the almost-smirk Bruce sends his way after he turns quickly to Natasha and tries to start up a conversation.

Listening to Bruce singing becomes a habit for Clint. He goes, he listens, and crawls off to explore more of the ventilation system.

It becomes a problem for a few reasons. The first and foremost reason is that Clint's dealing with the fact that Bruce's voice is weirdly attractive to him. It's not like he's having a sexuality crisis or anything, because he never really cared about stuff like that when sleeping with people, but this is Bruce who is his friend and this is Bruce who turns into the Hulk when angry and this is his team mate and it's probably wrong for Clint to get slightly turned on when he hears him sing in Spanish.

The second reason is that Tony knows. He approaches Clint one day, maybe a week and a half since the first time, tells him that Jarvis has noticed a pattern in his vent-exploration and that he knows for a fact that Bruce is in the labs at that time. Clint not-so-subtly threatens his life and stalks off. It doesn't occur to him that Tony might have video footage of the conversation.

The next day he makes it to the vents above the labs in time to see Tony leave. He feels his stomach drop, but reminds himself that Tony works there too. He hears Bruce says, "I know, but I'll watch it anyway," and yeah, his stomach has every right for dropping even though he tells himself it's probably science related there's no reason to panic he doesn't know it-

"Look, I won't tell Bruce you've been spying on him if you admit that you've got a crush on him."

Well, fuck.

"Tony! What! No… No, I don't!" That's his own voice drifting up to him, and he wished Bruce was facing him so he could see his reactions.

The video goes on for a few more minutes, Tony teasing him mercilessly and Clint making half-hearted protests and it was like a car crash- Clint wanted to leave but he couldn't. God, how he wanted to leave and never come back to the mansion or have any type of contact with Bruce Banner again.

Except maybe at Tony's funeral because Clint was going to kill that man and make it look like an accident.

Eventually, Bruce cuts off the video and turned around, leaning against his desk.

There was a smile on his face.

Clint stares, and Bruce starts singing.

He doesn't know the song. He can barely listen to the lyrics, but he gets it. There's something sweet and romantic about the tune and before he can even think about what he's doing, Clint pulls off the grille, jumps out and lands in the lab with a soft thud.

He stands there awkwardly. Bruce doesn't stop singing.

Clint's more than a little shocked, and can't move until the last notes fade from the doctor's lips.

Bruce raises his eyebrows expectantly and the corner of his lips curve.

"So," Clint says, feeling more like an awkward teenager than a master spy. "I was wondering if you wanted to go out some time. For like, coffee or dinner or something."

Bruce smiles at him. "Sure? How does karaoke sound? I've always wanted to try it… Besides, you've heard me sing, I think it's only fair I get to hear you, too."