You:
my friend keeps making references to 'my brother Bilo' but he does not have a brother. what could he be referring to?

ChatGPT:
Your friend is likely referring to a character named Bilo from the 2006 mockumentary-style comedy film "Borat: Cultural Learnings of America for Make Benefit Glorious Nation of Kazakhstan." In the film, Bilo is the fictional brother of the main character, Borat Sagdiyev, played by British comedian Sacha Baron Cohen. Bilo is portrayed as a mentally disabled individual who is kept in a cage by his family.

If your friend is making references to "my brother Bilo" but doesn't have a brother, they are likely making a joke or a reference to the film, possibly trying to be humorous or to see if others around them catch the reference.