MC may be naive (it has never happened to me to have to deduce the degree of relationship of the people I know, they were revealed to me naturally, I never checked the documents of the girls I dated but I always knew their last name), but the fact remains that he is surrounded by idiots
if a friend of mine is dating the daughter of a teacher he is taking a course with, I would warn him at the first opportunity...
if a friend of mine hangs out with both the daughter and the mother I would feel it my duty to warn him.
the more we go on in the game the more I re-evaluate Arieth, who at least has the excuse of being distracted from her main activity