I hope you come to some agreement.
I say this because with our first, we weren't going to find out, but we did on a third scan. We then told our closest friends if they wanted to know (who don't know the family) and gave JUST our parents the choice to know or not. They were sworn to not tell the great grandparents, and our parents were always going to be good at keeping their word.
This time around, had no plans to find out.
Have told DS from the start it is a suprise, to the point as a 4yr old he gets irritated by people asking what do you want, because he knows it will be a suprise! (I'm actually not keen on people asking him what he prefers, because at the end of the day, it's another person joining the family, so am happy he likes the idea of the surprise!
Anyway, DH was away for work when I had the scan and I found out (not really planned) I told DH, and a couple of times he has slipped up to friends and his mum (but not sure if his mum clocked, but know she wont say anything.) I was a bit frowny with him till I took the time to think, well he know views the baby as what gender it is, where as I think baby (even though we have a name now) and I too like to interchange she/he he/she to confuse other friends. I am all for the surprise element to give our family but it is difficult territory if a slip occurs.
With pressure from friends, go for the it's a surprise, that's what we have done and so far it's been accepted (fortunately not all our friends know each other, so for the 2 who know they can't slip up to anyone!)
I do think if your DH wants the surprise element with telling people, then let him have it especially as it's a first.