When she says about living together, she thinks about watching at his sleeping face, eating and watching TV together. And he thinks about other things.
@VincentYamato iirc Horimiya did it, it wasn’t explicitly stated that they did it but the panels were hinting at it.
Edit: Found the chapter, It’s Ch.37 Cold Rain. I like how the amount of comments is directly parallel to the amount of plot and story progression in a manga.
@EroZero yeah they did it, they didn't show it obviously, but the panel after they were lying naked in bed and all and then i think the little bro saw them or something xd