I think it is a short fic. No idea if there is a pairing or not, and it's definitely not The Enemy of My Enemy by Kadorienne (http://archiveofourown.org/works/1037081). Anyone? Thanks in advance!
(Not sure how to tag this - could use a theme for Asgard, for example!)
ETA: Found! It's We Give No Fucks About Your Antiquated Sense of Honor by anon at Norsekink.