Saw the raws and it looked like he really doesn't realize that shes a girl until later on in the story. He was flustered to see his crush bathing which is why he looked away during the outdoor scene. He loves the MC as she is even though he still thinks that she's a boy. There's still quite a few more chapters before it finally clicks to him that she's female
Episode 51 of the raws when things are getting frisky and the ML finally finds out that FL is a girl. Boom. https://toonkor.baby/%ED%99%A9%EC%A0%9C%EC%97%94%EB%94%A9%EC%9C%BC%EB%A1%9C_%EA%B0%80%EA%B2%A0%EC%8A%B5%EB%8B%88%EB%8B%A4_51%ED%99%94.html

wait, does edward already knows if mc is a girl? also, i forgot but is the mc under the impression that edward already knows? i vaguely remember that she does... but im not very sure.
lastly, im kinda waiting for the chapters to pile up but are there lots of moments between mc and cain too? or it's already build up that mc is for ml?