I believe this was a one shot but here it goes:
For whatever reason Loki decides to shift into a woman to the shock of Thor( not really the parents) Odin I believe just pretended that this was normal so not to encourage Loki's antic and Frigga was like "oh my" and then starts looking for old dresses to let loki have. I remember her telling Thor that she always wanted a daughter when he came to her for help on how he is be supposed to react this change.At a feast Fandral asks Odin for the right to court Loki, which everyone plays off as him being drunk. But then all the guys around the table/hall start to toast to Princess Loki saying thing like how beautiful she is blah blah. Which in turn pisses Thor off and he yell/demand/threaten that everyone get out of the dinning hall and he ends up screwing on the table.
Places this could have been read: I know i found it on a thunderfrost rec list, but as for where the story is actually located it was either norsekink livejournal or archive of our own... maybe
Thank You and Good luck