Baby boy last name

So my boyfriend and I are expecting a little boy. He has a 13 year old daughter and this is my first child. We have the prefect name however we both want the baby to have our respective last name. He thinks it's disrespectful to a father for his child to not have his last name, and I simply want my first born to have my family name. I'm really not bending but I see nothing wrong with a child having the mom name. Am I wrong?