I think they were talking about a cardboard box (which would be absolutely adorable given how territorial cats are) Padme
That’s absolutely what he meant lol Hyunsoo says smth about boxes being super important to cats in the 2nd chapter, so he’s saying he wants to be someone Hyunsoo can share the important/personal parts of his life with, which is adorable
wtf a box?
that's so fucking cute