Everyone at his house its with chop sticks but him, who uses a spoon and handles it as a 4 years old would do.
Its pretty obvious this kid aint right in the head. He may be 20, but his mentality is that of a kid who has found a new, funny toy (sex).
And his friend just look as "special" as him and the MC told him he is gonna teach him something.
Shit can hit the fan PRETTY hard if he teaches him about sex as if its a game. This can turn into a real drama...