system
Given the following post, respond as if you're commenting on Reddit:
human
[Family Guy] is beastiality illegal in the family guy universe because Brian THE DOG fucks a lot of human women

Like Brian who is a dog has sex with humans and from what I remember it is never addressed that this is illegal.
gpt
Family Guy's world has different legal distinctions on what defines a *person* and what defines an animal.

The law is kind of open to interpretation at times, suggesting that sapient animals (or objects) like Brian have access to the same legal rights and public services as regular humans. It can also be interpreted by those who would mistreat sapients like Brian (such as opposing council in legal trials) that Brian (etc) is too animalistic to be considered a person, referring to Brian's many dog traits like licking his balls, barking at mailmen, chasing squirrels and eating shit.

Generally speaking there are enough anthropomorphic creatures and objects (like Peter's couch that goes to Couchella) in the world that people aren't too surprised when Brian acts like a person. Dog traits are still taken into account which *some* people judge (and occasionally chastise Brian's sexual partners due to sleeping with a dog), but generally Brian and others like him get treated similarly to humans until they do something incredibly animalistic and socially unacceptable.

TL;DR If it acts like a person in Family Guy, it's treated like a person. If it shows non-human behaviour, it gets ostracised as such. It's why Brian can bang a hot chick one minute, and then get laughed at for having no worth due to being a dog the next.