The relationship is a Dom/sub one, with Tony as Dom figuring that Clint needed to be a sub after Coulson's death (he stays dead) and everything that happened with Loki, and this fic details how their relationship develops. No sex between the two of them; in fact the sexual/romantic relationship is with Tony/Pepper (Pepper was skeptical about this working out and was surprised when it did). Rest of the team initially not so good with it, but then, as they see the both of them are better for the relationship are supportive and increasingly helpful.
-In the beginning, Tony is not sure Clint is aware or willing to go along with this, but Clint doesn't blow up about it. Tony likes the closeness and the ability to have touch without having to devote his full attention to the other person - which is something that makes Clint twitchy if he's the recepient of, if it's for too long.
-Clint becomes sexually attracted to Tony. the way this is solved is that Tony sends Clint out to meet up with guys - first time, Tony feels like he's cheating on Pepper (Pepper reassures him this is not the case) and later, Clint's decked out as though he was going on a mission (so he can call for his Dom if needed). Clint is sexually satisfied; Tony and Clint still in a D/s relationship, Tony and Pepper still in a romantic relationship.
-Tony tells Clint, when they are going public, because they both want Clint to wear a collar (specially treated leather to be last through the battles and Tony-made-design) that Clint can tell Natasha if he'd like, but after the reaction (Natasha stabs the table) from everyone, Tony tells Clint, that no, he doesn't try to explain anything. In other words, Tony is taking responsibility despite how potentially creepy it sounds the way I typed it out, it came out sweet and a good-Dom-ness, at least from my perspective.
-Tony tries shibari on Clint and Clint falls so deep he needs Natasha speaking in Russian to pull him out.
-Tony pulls Clint out of flashbacks - first one in front of the team is during movie night; Clint ends up willingly blinded (his peripherial vision was too good for him to relax initially) and goes to bed continuing to be willing blinded.
-Last flashback is a bad one, after a fight; Tony's hurt, but everyone on the team helps (clean up first, to decrease scent triggers), rope for some light bondage (Pepper brings back enough rope for Tony to tie up EVERYONE), Steve brings over an ottoman so Tony can have leverage without as much strain on his hurt parts. Thor carries Clint.
So, y'know. I remember about everything except the author (I believe said author wrote other BDSM fic with sexual component), and the title. I need to book mark better.