Fairest way would be for all income to go into a joint account that is used to pay joint expenses, so house, bills, food, travel, childrens' expenses, car expenses, insurances, holidays etc etc.
Pretty much everything except personal spending money for adults (personal grooming, clothes, food and drink out that's not couple/family related, gadgets etc). Ideally you want some joint savings and both an equal amount of personal spending money, but it's up to you how this is managed.
Some people are happy spending out of one account, others prefer to separate off personal spending money so it's a budgeted amount and there are no arguments of the 'you spend how much on a handbag, golf lesson, spa day, in Starbucks' variety.
If you're keeping all your bills money and savings in one account, the Santaner 123 account is good because it pays 1.5% on up to £20k and cashback on bills that will offset the £5 a month fee for most people.
Other thing to check is that I don't know if £120 pw is enough to count for your NI contributions, so you should be getting CB in your name and he should be paying it back via his tax return if he does earn £50/60k+ so you get your full state pension.