They argued every time Natasha left to join the Avengers on a mission. Pepper didn't mean to start a fight every time Natasha got ready to leave, and the agent couldn't help but react to her attitude or even just the silent treatment. But they argued, even if they didn't want to.
"Every. Single. Time," Natasha growled, strapping her thigh holster onto her right leg.
"I didn't say anything!"
"You don't have to Pepper. I can see you working it over in your mind. You don't think I should go."
"Not to something like this. You're only human."
Natasha huffed, zipping her jacket up to her neck. Pepper was staring at the last of her weapons between them; the weapons yet to be concealed on her person.
"So are the others. Except Thor."
"Enhanced but human. Same goes to Barton, Banner and Stark – all human," she said, sliding a knife into her belt. "I'm quick, smart, well trained, heavily armed. And we have the same damn argument every time and I'm sick of it."
"You were hurt last time. Thirteen stitches."
"Not as many as Stark. And Clint had a fucking cast."
She swiped the empty weapon case off the table and waved it at her. "I was trained for this since I was a kid – longer than any of them."
"Except Thor – he shouldn't fucking count."
"We saved the world as a team, I've done more for this country, this planet than the rest of them put together and I will not be talked out of a mission by a damn secretary!"
Pepper slapped her, the sound loud and sharp, shaking her hand at the sting of it. Natasha glared at her, her own hands balled into fists now.
"I'm going before-"
"Before what?" Pepper cut in.
Natasha growled again, and stalked towards the front door. She flung it open and Pepper spoke again.
"This is insane you know," she said, voice softer this time.
Natasha turned and smiled.
She stormed off, angry words on her mind still instead of Pepper's soft sweet voice. Her stinging cheek helped with that. Getting worked up for a mission helped prepare her and stopped her worrying about or missing Pepper while she was away. Stopped Pepper from saying 'I love you' every time she left her behind.