It must therefore by a pagan fable.
This is quite possibly the faultiest logic that I have EVER seen!
NAU Matthew 12:
shalom b'SHEM Yah'shua HaMashiach Adonai 46 While He was still speaking to the crowds, behold, His mother
Matthew reports that he and the crowd thought that Yah'shua had a mother and brothers.
and brothers were standing outside, seeking to speak to Him.
47 Someone said to Him, "Behold, Your mother and Your brothers
are standing outside seeking to speak to You."