@Raskaro FMC getting asked out, accepting/denying is not the problem here. I'm not considering anyone's comments. The "visible" embarrassment/signs are clearly not visible to the MC. She gets embarrassed on her own and rarely holds an actual conversation with him which is fine because she is EMBARRASSED but expecting the MC to make a move is absurd.
What happens after he realises his feelings? Does he confess? It would be weird imo because (again) she rarely holds an actual conversation with him. Should he try to get closer to her? He's been trying to do that from the start but she indirectly shuts him down everytime because she is EMBARRASSED which is (again) fine but (again) what is the MC supposed to do in this situation? To the MC, she has gotten comfortable with most people (not the problem) but after the first very few chapters, nothing has changed between them. You can get close to someone and have some ACTUAL conversations and then realise your feelings for them. But if you realise your feelings for someone who does the aforementioned things, it's unnatural to act on those feelings.
It's clear that she's going to reject the other dude whichever way she does. I doubt it would be a simple rejection though, she would probably say she likes someone but how is the MC supposed to realise that it's him she's talking about when she isn't actually close to him? Being friendly with other people is not a problem but she's clearly more friendly with everyone other than the MC. He would obviously think it's someone else.
This "rant" was mostly because the starting chapters hinted towards something else. It would have been a better story if she got closer to everyone while simultaneously getting atleast a little bit closer to the MC as well and he gradually realises his feelings for her as he spends time with her. But they're not spending time together (not close to the time she spends with everyone else). Again, her spending time with other people is not the problem but expecting the MC to act on his feelings in these circumstances is absurd imo. Has she acted on her feelings in front of the MC? NO. Has she tried to get closer to him? NO. Has he tried to get closer to her? YES (only as a friend which is actually how relationships are supposed to progress but still YES). The MC has not done anything dense here. Maybe he will try to get closer to her after he realises his feelings but he has already tried that. Maybe he will be more aggressive but it would be weird if she says she likes someone else because almost everyone else is closer to her than he is.
Sorry for the rant and repeating points. Have a good day.