Natasha and Bruce
He hated that she felt that way. And he hated that there was nothing he could do about it. He cared, of course, but there was nothing to say that they wouldn't all be snatched up tomorrow, leaving her there alone. "Are you really planning on avoiding all personal attachments until we go home?" He asked, eyebrows raised.
Idly, he drew a pattern in the sand with his index finger. If he'd been paying attention, he'd have noticed it was the chemical makeup of radon. Because Bruce was, admittedly, a geek. "Loss is a part of our lives, Nat. We can't change that. Even back home, we lose people." As grateful as he was to know Coulson was...brought back somehow, he'd still grieved. And he knew, in their line of work, he wouldn't be the last they lost.