I'm going to apologise in advance as I do not remember much about the story I am looking for but I will do my best to give as much detail as I can.
The story that I am looking for was one where the Avengers went to Asgard and they needed help from Loki, I think. Of course, Loki being Loki would only talk to Clint so Clint was forced to spend time with the God of Mischeuf to see if he could get the information that the Avengers were looking for.
I forget whether this story had a pairing but, since I rarely read stories without pairings, I am going to say that Clint was in a relationship with someone in this story.
I'm sorry to say that this is all that I remember. If anyone knows the story that I'm looking for, I would be thankful if you could let me know what you think it is.