Is an American sized mattress! No legit, to me the thing that's throwing me off more than the bed is the thickness of the mattress, which to me looks like the type of bad 3d asset you find in webtoons.
Maybe we'll get another extra showing the text if it's so important? Which to my point about Maruto cutting stuff, the last panel of Hikari could have just as easily been her seeing the text from Yuu if it was important.
Seeing his dialogue with Haru and Yuki in chapter 43, this is securely the only one big fact he hidded from them and I see Yuu even now will try to avoid the sex parts in his explanation to Hikari. Probably he will be ambiguous about it, like his words to Hikari´s friends, about those intimate things, even if anyway Haru realized he is the boy of the "detailed erotic stories from Aya-chan". Depends from Hikari asks directly to Yuu about his... (non) virginity.
Almost irrelevant whether Hikari asks directly or not, because it's none of her business. Yuu is definitely under no obligation to share intimate details of his sex life with his neighbour, he's under no obligation to share those details with a friend, and I'm not even sure that he'd be obligated to share his past sexual history even if Hikari actually became his girlfriend.
