Loki was somewhat familiar with other holidays like Christmas. But Halloween was one of those things that he needed (Y/N)’s help to understand. Though the idea of trick or treating intrigued him when (Y/N) mentioned it.
Sadly, (Y/N) had to explain to him that trick or treating was something children did, not adults. Loki obviously found that a bit ridiculous, but it was a custom here, so why bother trying to argue it?
...That is until Halloween actually rolled around.
(Y/N) was in the tower’s kitchen, everyone else was out. Bucky was with Sam, Thor was in Asgard, Peter and his friends were no doubt out at a Halloween party...or something and the rest were at some big ‘event’ on TV, but Loki?
Truth be told, (Y/N) had no idea where Loki was, which was strange since Loki usually told him if he had somewhere to be. So, (Y/N) was alone in the tower, with nobody but his thoughts for sole company.
Until (Y/N) found him in the living area.
“Wha-? What are you wearing?” (Y/N) laughed. It was the cheapest-looking costume he’d ever seen like it was taken straight from a dollar store shelf.
“My costume, of course.” Loki had a look on his face that (Y/N) was very familiar with. A mischievous smirk as he held up two pillowcases.
Before (Y/N), with a raised eyebrow, could remind him that only children trick or treated, suddenly Loki was engulfed in green light and was replaced with a child.
“Are you coming?” He asked, holding out the second pillowcase with a sly look. (Y/N) hesitated for a second, but it was hard to deny the urge to break such a silly rule. (Y/N) morphed and changed into a child-like version of himself, taking the pillowcase with an eager grin.
The next thing he knew, Loki and him attached themselves to some group of children and were soon stocked on candy. Loki, of course, wore a mask. To avoid being caught, knowing the other Avengers would show up eventually. It was actually a bit scary, seeing as Steve appeared and almost recognized the two. But, he was thankfully pulled away by some fans before he could put the pieces together.
By the end of the night, (Y/N) and Loki had enough candy to last until next April. ...Or at least it would be that much if they were the type not to eat quickly. It would probably only last until Christmas at best.
Hiding the candy in their room once they arrived back at the tower, the two of them spent the rest of the night pulling pranks on Thor and the others once they all returned.
Sure enough, this would end up being a secret tradition between the two of you. Each one had some close calls being caught. But each time it would end with impish laughing, sweet treats, and snuggling.