After Hours by Ohcaptainmycaptain1918. This fic is a WIP but it is AMAZING, really, very honestly, all of her fics are amazing. IF you read Stucky fanfiction and you haven't read her fics yet, go check her out on AO3. She is incredible, better than most authors I've ever read (not to mention, her fics are incredibly hot)
"Steeeeeve. I'm just being honest. You are the one that keeps Tony and Clint from blowing half the world up." "Buck-" "What? I'm being honest. Does Captain America want me to lie about my birthday?" "Fine. But when IRS comes knocking, I'm not bailing you out." "Eh, we'll just blame it on Tony."