Wow. There’s a whole lotta opinion here. I am hesitant to Wade in, but maybe have something to offer. There is a lot of simply stating stuff as fact that perhaps isn’t?
firstly, the assumption continually on mumsnet that being older equates to being too tired to have more kids. Although OP mentions age, she doesn’t say her DH has said he’s too tired for more - just that he doesn’t want more. If he was her age, would people opine differently? He went into marriage with an age gap - if we are talking biology, I feel he needs to be understanding that he has married a woman much younger who will have that biology going on. Give and take. But if we leave the age thing alone, maybe just look at the situation. Of course, you cannot force someone to have a child and neither should you. However, I do NOT think ignoring that ache forever is necessarily a good idea. Yes the ache may never go away, but with two kids you’d feel a little better about the ache. I think the real point is the relationship. I feel it would be good for your DH to be able to understand your need and perspective - it sounds a bit as though he has shut you down without much empathy. He’s got himself a nice young wife willing to take on a man with three teenagers and he’s still calling the family shots. How much does he love you if you two cannot talk empathically to each other?
I am a mum of five and am that woman who will never be done. I had my youngest (5 months old now) at 41 and my eldest when I was 28. I felt better pregnant at 41 than I did at 28 and find parenting now so much better - I am more chilled and experienced - have better energy and am looking forward to the future more- but my first was so difficult - she’s autistic with other special needs and we didn’t know and i was never going to have any more! Number two was six years later and I loved it so much we just carried on. My husband has a daughter from a previous relationship and she has three kids of her own - so he’s a grandad as well as a daddy and his grandkids have aunties and an uncle younger than them. (He was a teenage parent, he’s in his forties as I am, so no age gap, but we aren’t spring chickens.)
having a special needs teenager and a bunch of other little ones is not easy at all, but it is life giving and we adore them all and it kind of keeps us going, even in the hard times.
My point is - it’s not always as straight forward as “he’s too old, you will be too old, baby care is hard” - imho, babies are easy!! I love babies! Try sleepless autistic teens with OCD and mental health needs! Babies are a doddle. I’m being facetious but I think there are more perspectives than age, amount of kids, blah blah. This is about the love between two people and the ache for a baby, which I know all too well. Try to talk properly to each other and find out the basis that you got married on - maybe that needs exploring.
good luck.
and for the record, all the grumpy oldies on here who couldn’t bear to have young kids in your forties and fifties - fair enough. I get it. My siblings are mostly of that opinion. But not everyone feels that way. Some people can thrive on that and provide a wonderful home for their young kids.