There's something off with Asahi-kouhai's vision...
Also is the comments window broken for anyone else on mobile? It doesn't open when I click the comments in fullscreen.
Schadenfreude is a little different, (schadenfreude is joy or satisfaction from another's pain or suffering) unless you're saying that the cheeky girl is experiencing schadenfreude.
That's kind of a weird comment but I'm pretty sure she's an adult. Just guessing off of the flashbacks their age gap doesn't seem to be too big and this guy looks like maybe he's in his mid-late twenties also taking into account his "largeness".