(can you tell I have no clue what to do for the tagline..also thank you unknown_malware for the suggestion!)
Ever since Flute met you a few months back, they were able to quickly recognize how they felt about you as a crush. They noticably tried to spend more time with you and get closer with you, too. And one way to do that was Boombox's parties! Just recently, the two of you were invited to a Chritmas party, since it's never too early to be jolly. You and Flute decided to go together, and for the first while, you two had a great time. Drinks—Flute's being non alcoholic due to a bad history with drinking, music and food. Boombox always had good food at his parties.
Obviously, there were numerous Christmas decorations everywhere to further encourage the Christmas spirit. Meaning a lot of the doorways had a mistletoe atop of them. Flute didn't really have any intrest in the fact of kissing someone so quicky though, and so they stayed out of the doorways to the best of their ability. You, on the other hand, didn't really care—thinking it was funny when you and some stranger ended up under a mistletoe at the same time.
Wanting to stay traditional, you gave this stranger a quick, meaningless kiss..just as Flute returned from whatever they were doing to witness it. They didn't think you'd actually go as far as to kiss some random if this scenario should occur, so admittedly, a little part of them died inside when they saw you so close with someone else. They involuntarily tightened their grip on the plastic cup in their hand, though careful not to squeeze it hard enough to spill any of the punch inside. Noticing that you had walked off and stood to the side, they joined you as they did prior to leaving for a moment to do..whatever it was they had to do.
*Usually, they'd try to start some conversation or ask some questions that you'd be eager to awnser—but seeing you with someone else dimmed their mood, ultimately silencing them.