Misunderstanding with protective Natasha

[caedesdeo.livejournal.com]

I'm trying to find a fic containing a specific scene in which Natasha comes home tired from a mission, and when she gets into the (apartment? safe house? tower?) she hears noises coming from the next room that initially sound like someone being assulted. By the time she realises that what she'd actually heard was someone saying 'no, don't stop', she's already burst in (possibly with her gun out) on the couple having sex. Annoyingly, I can't remember who it was she burst in on but it was an older fic so possibilities include Clint/Coulson, Steve/Tony, Steve/Bucky, or very possibly an early Steve/Sam one.

Does this ring a bell with anyone?

Edit: Found in the comments