Natasha + John
"We have a...kind of signal, that's just ours. Came up with it when we were kids. I responded the right way, so she knew it was me," Natasha replied quietly, then smiled a little - glad that he wanted to get to know Yelena. Both of them were very important to her, and it was important that they get the chance to meet as well. She'd always kept her Avengers family and live very separated from Yelena, Alexei, and Melina - but she couldn't really avoid that here, which meant the best thing was to just let it happen and hope things went okay.
Laughing softly at the wince and response, she gave him a perfectly innocent smile. "Then it came across precisely how it was supposed to." Sliding her phone back into a different pocket than the one she'd put it in before, Natasha smirked but let her head rest lightly against his for a moment.
"That's Captain Muscles to you. And he'll survive - it'll do him good to not get everything he wants right away." Natasha arched an eyebrow as she looked back at John. "And I'm sure you will, but the video is password protected. Even if you do manage to get the phone from me, he still won't get to see it."