One thing I'm not clear on - and maybe I am just being really dense! - is if he's paying the rent, and bills - so council tax, electricity, gas, tv licence, water - is he also paying for all food as well? And if so - what do you actually spend your money on? Sorry if you've mentioned it but if you want to be a SAHM, what costs do your incur for the daughter you receive maintenance/child benefit for if your DP is paying for the cost of housing and feeding her?
I probably am being a bit dense, so don't jump on me but apart from clothing, if she doesn't have childcare costs because you're a SAHM, and he's paying the rent and food bill....maybe he's wondering if you should be contributing a little to the shared bills?
I hate this emphasis on the woman's wages paying for childcare - like it's her responsibility alone! - but believe me, when I'm on ML in 15 weeks time, my SMP is going towards the rent! It's not going into my pocket, it's going into our shared family pot because DH and I have mutual responsibilities to keep up rent payments, feed ourselves and our new baby, pay bills and keep up with general life expenses.
When I'm back at work - yes it might just be easier for the childcare costs to come out of one salary but it's just swings and roundabouts! Whoever pays childcare obviously doesn't then also have to contribute to the rent. It just gets added to the overall shared cost of living between us, and that overall cost is allocated between us. It actually makes NO odds who's actually paying physically for what, but more important that the overall monthly payments for living are kept up.
To be a SAHM or a WOHM is entirely up to you but if I were you, I would be very concerned about my future. I don't necessarily hold the same ambitions for my career now that I am pregnant that I did pre-pregnancy, and I do daydream about how lovely it would be to be a SAHM - but only in the short term! A couple of years maximum. I tend to thing very long-term and you have many decades of wondering what the hell to do with yourself. Yes - of course conceptually you could start a career in your 30's - but actually how realistic is that? You haven't even started your chosen career yet - unless I've missed you saying you have! And you're not just talking about staying at home for the next couple of years - you're discussing ANOTHER baby that would keep you home for several years yet, between caring for them all.
It is a shame because it is VERY valid to stay at home and raise you children - but it is a choice, one that will always have a downside. There is an awful lot of merit in forging a career for yourself, and not just financially. Neither man nor woman has it all - the man goes out to work, he doesn't "have it all" either. He misses out on precious time with his children.