It was another day of class, and the heat was seeping into the classroom making the lecture call stuffy and nearly unbearable. The sun streamed in through the windows and hit a handful of unfortunate desk chairs, heating them up, and also Bruce Banner as he sat at his desk and fiddled with his computer in order to advance through the slide show.
His intro to chemistry class was going to start in ten minutes and he was adding some notes to his powerpoint on defining an electron from a proton. Bruce raked a hand through his hair and stifled a yawn before stretching in an effort to get some airflow under his shirt. While fall should be creeping up on them, that wasn't the case for the day, which had caused both Bruce and Tony to grumble about global warming over their morning coffee.
He heard the door open and Bruce pushed himself into a proper sitting, and more professional, position but didn't take his eyes off the power point quite yet, "Good morning."
"I don't even get a kiss?" The words caused Bruce's eyes to widened.
"Erm – uh," it wasn't until he spotted a head of red hair that he relaxed. "Natasha," he breathed as she moved around behind his desk and wrapped his arms around his shoulders, resting her head on the crook of his neck from behind. "I had thought you were a student."
"You wouldn't give me detention, would you?" There was a teasing hint in her voice as her lips ghosted over his ear and he chuckled.
"They don't do detention in college, Tasha."
"I wouldn't know." Bruce turned and kissed her on the cheek and she offered a grin in return. After a few more kisses, Natasha moved to the front row and took a seat in a chair on the end much to Bruce's amusement, and not ten seconds later the door opened to reveal the first student. Slowly, one by one and group by group, they began trickling in until they entered in streams and class was beginning. Bruce realized partway through the lecture that he never was able to get those electron and proton definitions up.
Bruce was standing at this point in the lecture, pacing across the front of the room as he spoke and used a lazer pointer to direct the slides – a green one, because apparently one of the kids was color blind and it was easier to see rather than the red color and it had taken him all of half a second to decide to switch for the kids' sake. "So as I've told you, protons and neutrons are in the center of an atom and those make up the…?" He trailed off until a few kids answered 'the nucleus' and he carried on. "Good, then electrons surround the nucleus. Can anyone tell me what charge these three particles have?"
Peter raised a hand, "I'm positive that electrons are negative." There was a vague chorus of snickers and groaned, and he grinned impishly. "Protons are positive and neutrons are neutral."
Before Bruce could respond that the kids were right, he saw a raised hand, poised above someone's head. "Yes?" This word died in his throat however as he saw who owed the hand – Natasha.
"Is it true that particles with opposite charges attract?"
"Uh," Bruce trailed off once more and watched as her eyes sparked in amusement. "That is true."
"What about socially?"
There was a strained sound from the back of Bruce's throat, at which point a few students began muttering amongst themselves. "I would say that it depends on the people. Sometimes a calm person needs someone to liven them up, or a reckless person needs someone to help them keep a level head," it went without saying that this statement related to Pepper and Tony and he could see Natasha give the slightest hint of a smirk. "But sometimes two people wrapped in confliction need each other, too."
Wordlessly the woman stood, crossed the room, and trailed one hand from his front across his hip to his back and kissed him once on the lips and he hummed into the contact despite the fact that two of the kids had begun wolf whistling and hooting even as Natasha passed him and left the room, leaving Bruce standing in the middle of his lecture hall attempting to flattened his shirt and calm the rosy flush of his cheeks.
"Was that Black Widow?"
If the class wasn't talking before then, everyone burst into a chorus of questions after that.
"Class dismissed!"
AN: I'm not really sure how I feel about Bruce/Natasha if I'm being honest, but since it's canon I figured I'd throw this in there. Although I definitely might play around with a Tony/Bruce one-shot later as well, seeing as I figure these are connected one-shots but also can be read as dis-connected stories so you can easily skip one chapter and read the others and not be confused for the most part, save chapter one if you want to know how Bruce got his gig. Anyways, thanks for reading hope you like it!