Help!How do i watch my little boy grow with tribal marks on his face

My name is......... And I'm in my early thirties.Married with a two year old son.My husband works in a bank and I work with the federal government so we leave home very early.There's a nanny that takes care of my son during the day and she leaves as soon as either of us is back from work.The money we pay her is a bit much so my joy knew no bounds when my mother-in-law came from the village to spend two months with us.I was more than happy because it means the salary we pay our nanny will have to stop till my in law goes back to the village.Luckily for me,it didn't take my son much time to settle down with his nanna.
One day,I got back from work unusually early that day,went into my son's room and I found him sleeping peacefully.I was almost tip toeing out of his room when a second thought told me to move closer.I did and to my greatest shock I found three tribal marks on my poor boy's face.Well,according to my in law,She had organised this plan without the knowledge of my husband and I to give my first son tribal marks because according to some stupid tradition,every first son of the family must have.My husband is not the first boy so he escaped it.Please readers help me find a solution to this.How do I watch my little boy grow up with tribal marks on his face in this day and age.Who still does that?I'm still devastated.I want my in law out of my house.I hate her with every fiber in me.I need answers please before I lose it.