You are outside getting your mail, and a bird flies in, so you try to catch it in a cup, but when you catch it, it bites your finger a a drop of blood came out. the bird flew away after that.
You think "Oh, shit! That bird just bit me! now I'm gonna have something else to hide! God Damn It!"
The wound heals quickly, and you quickly go inside, and get naked down to your underwear, you feel a pain at your spine, and think"Oh, great, wings, how the hell am I gonna hide wings?" Just as you thought, wings sprouted from your back, but they looked like dragon wings, not bird wings. you figure it makes sense even if it isn't covered in feathers.
Once your wings fully grow in, you put on the coat to see if you can hide them, "They aren't too noticeable," you say to yourself. You also just realized, that with wings attached to your back, you can't lean back in a chair comfortably.