Loki and the Two Avenging Reindeer (смешанная)

Bored after his stint as a king in Asgard, Loki decides it's time for some mischief on Midgard. If nothing else, the Midgardians are interesting. But he is quite tired of being called names by the Man of Iron--and so he casts a shapeshifting hex on Tony Stark.
At the last moment, Thor gets in the way and is also affected by the spell. And now the Avengers are stuck with not one, but two Avenging reindeer.
It would be minor mischief--except it turns out that, contrary to popular belief, regular-shaped Tony Stark and Thor both have brain to mouth filters, which are completely turned off when they're animals. And they both think Loki is just awesome and lickable and are very interested in tapping that.
Or, the story where Loki does what he wants (as usual), Tony is a worthy mate (as expected), Thor is jealous of both Loki and Tony, Thor and Tony cross horns, Bruce is a good bro and Steve is traumatized. Also, Frigga is a posthumous matchmaker. Because that's how she rolls.