Like this so far, just going to rant about a realism flaw:
I know this is some type of (anime logic/humor) contrived event to get the mc to accept the confession...
It's still really shitty or borderline retarded to not tell someone they are a boy before confessing... And then telling them RIGHT AFTER?!
Why would you assume they know??
Without any sarcasm whatsoever, you really might be amazed at how "realistic" this actually is. For one, being a femboy/non-normative is already really socially alienating in most real spaces, so it's not always those people's faults for "not being upfront"; they're dealing with an immense amount of fear and pressure to keep it hidden.
Even if we ignore that though, it's just as cut in dry in the MC's direction: if you signed up for something and find out it's not what you want,
it's on you to have the balls to admit it. Not saying this is what your perspective is, but imo being cagey about something people might
judge you for (violently, even irl) is nowhere near the same realm as just being a cowardly little bitch who can't be honest that they're just stringing someone along and/or allowing a relationship to play out that they want no part in.
Yeah, not telling MC beforehand
just in case he's denser than a diamond is kinda shitty, but we're talking anthills compared to mountains in terms of shittiness; irl if MC wasn't into it they break up and move on, whoops sorry you had a crush on me but at least now you can find someone else. MC deciding to stick around when it's not what they really want though...that's many, many levels of intentional ignorance and cruelty (even a kindergartener has enough self-reflectiveness to know it would suck to have someone fake caring about you), and yet somehow real people do it, and they do it for weeks, months, even years, all just so they can milk their "partner" for everything they can get.