I think this continuation from another, where Giyuu was mentioning his new breathing form: Dead Calm and Shinobu said he shouldn't be naming it after his social life. Giyuu then followed up with how he didn't name it after his social life, he named it after her dead sister.
He has been traumatized to such an extent that he has lost all will the live…also he keeps muttering “it should have been me” but I think he’s talking about him and Nezuko
she was mourning her sisters death she was cutting onions she was giving shots and giyuu just got his she was bullying giyuu for being lonely again and he walked away already
If you don’t understand, basically Tanjiro smelled Giyuu but it was shinobu who had his scent and why she had his scent is because they went to eat ice cream:)
Oh wait- this has a completely different meaning then what I thought it meant So, I thought that since tanjiro smelt tears it was giyu so he goes inside of the room and sees shinobu there and realizes that shinobu made giyu cry😅