There's a track on Taylor Swift's 1989 album called "You Are in Love", which she wrote after being inspired by BFF Lena Dunham's relationship with Jack Antonoff.
One of the cutest lyrics, however, makes reference to keeping his T-shirt, while he keeps his word.
The words are:
"Morning, his place / Burnt toast, Sunday / You keep his shirt / He keeps his word / And for once you let go of your fears and your ghosts / One step, not much / But it said enough / You kissed on sidewalks / You fight and you talk / One night, he wakes / Strange look on his face / Pauses, then says / 'You're my best friend' / And you knew what it was / He is in love."