Pressure for a name... From family.

So I need help I have 2 children with this man and I'm only 12w3d so it right now is early so I don't know the gender. We have a girl and a boy and well his dad is pissed we won't name him Mark Allen n 3rd. Well because my son's name is Daniel Allen first off and it is his child as well so he had a previous opportunity to do it. Plus he wants the baby names after him my fiancee does not like his first name and thinks only the last name matters which will be his like our last two children. He thinks Mark is too plain which he grew up with the name it's his name he knows best and decided not too. But seriously it's a lot of pressure I feel I can't name my son or any of my kids I feel without their input which ok I know my kid I can name him or her what I want but the pressure is real. We want to name him Benjamin (don't know a middle name yet) but we had that picked out before I was pregnant even. i just hope I have a girl at this point because I'm over it and if it's a boy I have so many more months to hear him complain about it and try to change my fiancee mind when it's my choice too!