
if i were him i would just say that we never did anything naughty and even if we did, it's none of her business. Why do protags always panic in a situation that is pretty easy to handle..

Because that's his personality, he's an insecure poor middle school boy. Yes, it's annoying, but it's not like a character with that kind of construction could just up and slap everyone's faces with facts and logic, that would be unnatural and the entire plot until now would be invalidated. He's probably gonna cry and run away or yell something at them.
I actually kinda like this type of shy MC, cause then the character development is more relatable to me (even if sometimes I wanna punch their faces for being so dumb)
why does the author suddenly make the male leads....scum and bastards