Wings

Anyone who has wings (particularly if you have.. ehhem. adult-sized wings) knows this is impractical, and it's way better to just use snaps or buttons.

Guess it works if you got tiny ass wings that wouldn't lift anything. Bumblebee ass mfer

Tiny wings are very much capable of lifting heavy things, but they have to flap super quickly. Humming birds have really tiny wings compared to their size, but since they never glide, it's not important. The bigger issue is the position of the wings.
Since the line between the center of mass and center of force (the wings) is not perfectly vertical, Pit would lean forward during flight. His body would be suspended under his wings. This means his body is blocking most of the wind generated by his wings. So he would have to exert even more force to stay flying. Plus, your arms would get super sore when all that force is pushing them forward.
It should also be noted that Put doesn't have the musculature to support this level of force. His biceps are connected to his arms, not his wings, so he must have a separate set of muscles specifically for his wings. The only suitable anchor points are his ribs and spine, but in no art do we see the require muscle groups around his shoulder blades.
In short: I don't think this is real, guys.
- Hummingbirds get lift on both strokes, forward and back, and require an extremely specialized set of wings to do so.
  In regards to your comment about muscles for lift, birds have a “keel bone” (like a boat) which is where the anchors for their wing muscles are. Equivalent to our sternum. So the muscles for flight in the image would be on the front, not the ribs or spine.
- What if he's just really really light
I'm a grower I swear.
- That's what we all say. I mean they

I would be so afraid to snap a feather when undressing

I would guess that if you had wings with feathers you'd be intimately knowledgeable on the tensile strength of them
- You would think but tell that to the number of times I break a nail doing routine shit

Wings wound not "slide out" so easily when taking off the top. They only slide one direction.

Most important, wings of the span necessary to carry a 40-50 kg person wouldn’t fit inside the arm holes of a tank top, or work with this technique.
- If we are getting realistic, a pair of wings is always accompanied by a very big pair of chest muscles. Imagine a human with pectorals in proportion to the body as a dove.
- With the marvel of modern engineering, they do pretty compact wings able to carry 80kg humans, https://youtu.be/ilx8Ch0eOR4 (Sorry for sharing marketing video)
  So in a fantasy world, you could imagine so compact wing part of human body
You don’t slide them out, silly you roll the shirt up, and take it off inside out.
They're fictional, mate. Humans don't have wings. You gonna harp on that, too?
- Lemmy has a bit of an issue with taking memes or random stuff seriously. I've noticed it in a lot of my posts. Me often just saying "It is a meme" in response.
So, they need a shoehorn like device the cover the wings and allow sliding?
- Is keeping the shirt from flipping inside out a requirement for some reason?
  I imagine it would be more like lift the bottom front of the shirt over the top of your head and tuck behind neck so that full chest is exposed, fold arms in to insert hand through arm hole on same side as that arm and then push arms forward to leave shirt hanging off wings, reach behind while leaning back to grab and pull shirt off wings downward in direction of feathers.
  Either that or how my wife takes off her bras that don't have clasps, push shoulder straps over and down arms, lift arms out so only chest band is holding on, then push the whole thing down chest and over hips and step out of it. That way it doesn't have to go up and over the breasts.

Here is the source: https://www.tumblr.com/ask-crow-aus/759912849861754880/slytherin-assassin-lattemonstr-aishishiii . It is one reblog further down, as slytherin-assassin deactivated their blog and lattemonstr apparently has no post on their blog, probably deleted when they moved on to a different blog.