There are so many women in this position. If you are going to drop to part time or be a SAHM - please for your own sake, agree to have your pension topped up as a family expense and keep your hand in the job market. Your husband will make all kinds of assurances but those will disappear along with him, in a divorce
As someone who is now 50, I can assure you that getting a well paid job after a big career gap is not easy. Having the stamina to tackle a big job at this age, is another matter entirely!
Having gone from 2 incomes to one after a divorce, it's hard to manage. I haven't had a holiday in 5 years as I've needed to prioritise paying down my mortgage and topping up my pension. I will be doing pretty much the same till I retire.