The mum of the baby revealed that the name - chosen by her Irish husband - is facing major backlash from one side of the family.
Taking to Reddit, the new mum explained that her husband had always wanted to call his son Oisin, so it holds significant meaning for them.
Her husband is originally from Galway and had always let her know that this was what he wanted - even back when they started dating.
So, they came to an agreement that if they ever had a boy, they would name him Oisin.
Despite this being well-known among their family, the mum’s brother and sister-in-law (who have no Irish roots) decided to name their child - who was born two months earlier - Oisin Miguel.
“My brother and his wife have as much right to name their child whatever they want. I do not own my name. I have no right to dictate to my brother what he names his kids,” she wrote on Reddit.
Despite this, she stuck to her guns and named her little boy Oisin as well, just as she had planned to do for years.
As soon as her sister-in-law found out, she made it clear that she was not happy about the situation and insisted that she change her baby’s name immediately or use his middle name ‘Daniel’.
“She has flipped out that two cousins will have the same name. She is nuts because our family is Hispanic, and half of our cousins are named Carlos or Camilla,” the mum went on to say.
“My husband’s family thinks the whole thing is hilarious, my family thinks my sister-in-law is a weirdo, and she thinks I’m an a**hole for copying her.”
Since posting her story, thousand of people have been backing the new mum and many people are even leaving comments in support of her decision to stick to her guns.
What are your thoughts on the situation? Let us know in the comments.
