The way you phrased it makes me think of a riddle lol :)[br][br]If
you call anyone anything different behind their back, it's an
insult even if it's a middle name, especially so if you use it
against them in a derogatory way. This is true for just about any
thing, and I'm sure this stays true across most if not all
cultures.[br][br]You can use third son as an insult for certain as
it pertains as "always third, never second or first" in a family
which is in a way disgraceful. I'm sure you're aware that in Japan,
traditionally speaking the first born is the one who leads the
siblings and the one who is first in line to continue the family's
lineage.[br][br]It's actually not that uncommon to name children
based on their birth order and the stigma is still a thing to this
day. I hope this answers your question.[br]