Don't want teenage brother there

I would like some feedback. I'm 17 years older than my youngest half brother, who is still in high school. I nicely (I thought) told my mom that I wasn't confortable having my brother come with her when my baby is born this summer.  It's my first baby, and my younger sister, who has had two kids which my mom has brought my brother along for both births, has told me that my mom doesn't have him keep the tv down while the baby is napping etc, and it has made the experience really hard. Also, we aren't very close though I do love him, we are just so far apart in age and across the country from each other. I want to focus on figuring out how to be a mom and then host other family when my husband and I settle into a routine. My mom responded that if my brother isn't invited then she isn't coming at all. I was shocked. Was it inappropriate for me to make the request to wait a little while before bringing a 16 year old boy?