Looking for a fic where Harry presses his thumb pad into Draco’s tongue

And Draco is salty because he thinks something along the lines of 'Harry presses his thumb pad into Draco's mouth and it's fucked up but Draco likes it because of course he does, he likes fucked up things." It's on Ao3, nearly certain it's an 8 year fic but it definitely was at Hogwarts?