He knows it's cheesy, and he knows it's so cliché that he shouldn't be pleased, but he can hardly suppress a grin when she wears his things.
She's stylish and very attentive to what she wears, even to bed—always something classy.
Unless it's one of his big, baggy shirts which totally doesn't adhere to the usual standards, that is.
She doesn't ask for them. She doesn't have to. Maybe she knows that it makes him happy to see her in them—like it's a sign of ownership or possession. Though if he worded it like that, she might punch him for it. Perhaps… Sentimentality as the reason instead instead. The knowledge that when she puts it on, he catches her pull the collar up to her nose to smell him…
It warms his heart in ways he can't describe.
He knows by that one gesture that she wants him around—wants him to be there with her, and to be close, and to envelope her and just hold her forever. It soothes worries he has, and it makes it hard to do anything but love her, because how can he not when she's so adorable?
He doesn't say anything out loud when he sees her wear his things, but his smile speaks much louder than his words ever could.