BIL and baby name more wwyd

[Rosae]

Inspired by the recent threads about baby names. Has been on my mind for a while.

Soon after our lo was born my sis and get family came to visit. When arranging this she asked if we had any nicknames for lo. I said yes and told her and she said good cos BIL was wanting to know what to call her - they already had the full name. I thought this was a little odd,especially as they have insisted their children are called by full names and call my brother's kids by their full names. However i was busy with my newborn so didn't ask.
Next time she visited I remembered and commented to her that it was weird. She rolled her eyes and said that it's cos we picked the name they had picked for if their boy was a girl and he's a bit miffed so doesn't want to call her the full name. We were unaware they'd had a girl's name picked, tho tbh it wouldn't have changed our choice as this was a name I wanted for a baby since childhood. I am very glad they didn't have a girl!
It's not really a problem as we have many nicknames for her but I have noticed that he is always very careful to use her nickname and corrects his children to do the same if they use her full name. Would you say something?

[Rosae]

I think the eye roll was cos she thinks he's an idiot for this. He's usually very laid back but apparently sees this name as his son's name!? Though she thinks he's being stupid I don't think she'd back me up on making a fuss cos she sees it as not a big deal cos we use a nickname anyway. But I do feel weird when he corrects his dc because they look really confused, especially if I then use her full name. Plus one of them has autism and rarely communicates with anyone so I was rather irritated that he corrected him as he then backed off from what was a very rare interaction between them.

[HorridHenryrule]

Don't have him in your house the only person who will feel awkward will be your daughter. I know how that feels coming from an awkward family myself. I protect my children from foolish people. Is your sister thinking about how your child will feel. No they are being selfish together fuck your daughter it's about their feelings. What are you teaching your daughter by allowing stupid people to treat your daughter like that.