He’s never going to stop looking for him, Natasha thought, and averted her eyes; their intimacy had somehow become terrible and painful to watch. “We’ve really got to hope he’s not here for Barnes,” she told Tony, “because if he is: I’m not sure we’re going to be able to stop him.”
Adult, time travel, not-CW compliant. Because when there’s a portal, of course Steve wants to use it to rescue Bucky – only Natasha & Tony absolutely have to stop him. This combines outside POV, first time and post-WS feels in the most beautiful way.