In general, I would say that the options for giving children surnames are:
- Give children your name.
- Give children his name.
- Double-barrel.
- Pick a totally different name and all take it.
Obviously, this is assuming you keep your surname - if not, then options 1 and 2 are the same, and option 3 doesn't exist.
There are some compromise solutions too - my dcs have my name as a middle name but his name as a surname - the reason it was that way round was because a) we weren't married so he wanted to feel that dc1 'belonged' to him officially in some way, which I thought was fair enough (we got married later), and b), one factor which surprisingly no-one seems to have mentioned, my surname, though lovely and meaningful to me is a real pain to spell/pronounce and his very common surname was a lot easier to use for everyday purposes. so going for the easier or 'prettier' name may be a factor for you.
Double-barrelling wasn't an option for us, as our surnames are both quite long and it would have been a right mouthful. But that might be another compromise that might work for you??
If you do go for the middle name option, funnily enough one of my dcs has chosen to double-barrel in effect, by using her middle name as a de facto first surname. As she likes it and wanted to signal her closeness to me and my side of the family. :) So even if it's officially a middle name, your dcs may decide otherwise!
That sad, I would have been very, very concerned had my dp, now dh, laid down the law on any matter as important as that without considering my feelings and without us discussing it and making the decision as equals.
It doesn't bode massively well for your future relationship together. Your dp does sound rather controlling at worst and insensitive and casually sexist at best.