As far as Hermione was aware, Draco didn't know of her infatuation with him nor her relationship with Theo. She was well aware that Draco and Theo had been in love with each other since their Fourth Year. Even breaking up, didn’t lessen Theo’s devotion to Draco. She thought maybe most girls would feel jealous or uncomfortable with how much her boyfriend pined after his ex, but not Hermione. Something about the three of them felt...right. She knew that, like her, there was nothing that the Slytherin Prince would not do for the Nott Heir, any extreme was reasonable if it just kept Theo safe. 