Alright, probably not the most original headcanon but I think Arthur refuses to remove his grubby mud crusted bathrobe and fiddles with the edges of it so much that the bottom edge is just bare threads like those ancient decrepit remains adults will have of their baby blankets, just a little bit of fuzz and then flat grubby strings
If his bathrobe looks like that imagine what the rest of his clothes look like!
His bathrobe is hanging on for dear life, i imagine that when its just a couple pf strings and unwearable arthur would tie it onto his towel, or hold a very dramatic funeral for it.










