Partner now insists baby names must begin with A after our agreement

Fuck that!

My baby my rules! (with DH input)

Dont do that, its annoying when people dont go by their real name when they use any kind of public services

As someone who has the same initial as their sibling, I hated it. It was really annoying when post arrived just addressed using the initial and surname. Anyway, I made sure my two DC did not have the same initials.

Why have you taken on the surname of a man you are not married to? If you want to be married, get married, but don't create the illusion of marriage for a man who hasn't married you. My DS1 was born before we married, I insisted that since I carried and birthed him that he would have my surname. It was a complete non issue for DH and it was very easy to change DS's name once we were married.

How sad that your DP and family might see your child as an outsider just because they have a different initial.

Since you are not married, if he won't sensibly agree to a name with you, you can take baby to the registery office alone and name them what you like.

I’ll give him the benefit of the doubt based on your posts that he genuinely misunderstood (I am VERY doubtful). Well, he misunderstood and now you have clarified the situation. He got the surname so you get the first names, and they will NOT be starting with A. He is unreasonable.

I would also be worried about your DC being pressured into getting a shitty tattoo that they do not want (who wants their own initial tattooed on them?). If you break the tradition, you remove that risk.

I don’t know what you’re worried about, OP, Anarchy is a lovely name 😂

If you want to compromise because you’ve said you prefer his surname anyway you could do a hyphenated first name with the first or second beginning with A?
ie Ava-Louise (if Louise was on your name list) or Daisy-Anna (if Daisy was on there).
I chose the first name of our first as my DH carried on the tradition of having the same middle names as his Dad, Grandad and Great Grandad, that was our agreement.
It was important to him and because they were middle names rather than the first one despite me not particularly liking them as very old fashioned, I didn’t have a problem with them.
I named our second one, first and middle names and then we jointly named our last one.
There is no point picking a name you hate because it starts with the correct letter, I would suggest to him that you wait until baby is here and see what they look like.