No hate or anything just an observation

Why in manga, when the mc has like a bully or a rival or some shit, come to the mcs house and their parents are like 'oooooh a friend" and the MC is like "ummm no that person isn't a friend" they just ignore what their kid says and invite them in, like damn, if I told my mom somebody is not my friend she is not going to be like "nahhhhh yes they are" she is immediately going to be like "why they fuck are you here?" and then they get treated all nice trying to imply they aren't so bad, and I am like "that's not how that shit works dude" this latest chapter just proves that hahahahah