krusca:

clint and tony having fun makeout sessions and sexytimes and maybe even after one (or both of them) get together with someone else cough stevetony clintasha their SOs arent always around and they just really crave physical affection so the other avengers will find them curled up together on the living room couch asleep (steve walking in on this and he just smiles and throws a blanket over them and sits down and draws them while natasha somehow always finds a way to snuggle in between them and tony waking up hours later to shriek like a little girl at the super assassin staring at him an inch from his face)

(and clint and tony never bother to put a label on this and no one really questions it everyone just kinda accepts it yep yep)