Name drama

[Firefighter268]

SIL and brother called DS Charles, he is only known as Charles. I am aware this could change when he gets to school however parents insist on Charles.
I told my mother if my baby (14 weeks pregnant) is a boy he will be Charlie, Charlie would be on the BC after my husbands dear grandfather who is no longer with us.
Mother was horrified and said I could not use the name

please give me your thoughts

Don't call your baby the same name as his cousin. SIL did this to us without even asking, named her third baby exactly the same name as our first who was born 7 years earlier. It is so confusing when parents in law refer to him. You always have to.ask which.one.they are referring to. What's worse SIL doesn't want anyone to use nicknames and insists on the full name which is what my son uses. It's really annoying

We have 2 first cousins with the same name, we thought it weird when the younger one was given the same name as the older one, but no one cares now. They are about 15 years apart in age, though, and don't live in the same area, so there only a few odd family occasions when they are together.
It would be weirder if they were of a similar age or if they were likely to spend much time together.

No, just no

You can’t use the name. It’s the same name. Charles will probably want to call himself Charlie when he’s older.

It will make you look invasive and weirdly attention seeking if you use it, and will probably affect family relationships to some extent. Create drama.