Ok, I’ll bite.

First, there was a guest in the home being insulted and the hosts decided to sit there like passive aggressive chumps. This is called the bystander effect, as this person is a member of a group regularly targeted for acts of bullying and violence, and offenders can be charged with hate crimes, so…favors were done for none of the diners. Just bc she only gives a shit about her sons, doesn’t mean they’re they only human beings who actually mattered.

Second, it seems doubtful that these family dynamics just came into existence: likely, the parents always preferred the more extroverted younger son, interpreting his bullying behavior for “fun” and “confidence” and what they’d imagined for a son to be as a brand ambassador for their legacy. My experience is that most parents don’t really love their kids as unselfishly as they believe by a long shot! They’d much rather the bullying gets the message through to the bisexual son that they hate his “uncomfortable inclinations” and find a female partner, so this tacit approval of the younger sons behavior is the first step in helping the older son self-deport from the family if he won’t.