I am in a similar situation where my man is working and I am a stay at home Mum on benefits at present.
He insists on paying for everything, but it doesn't feel 'disempowering', because I do see that he is a naturally generous person and understands my financial situation. I would be the same if our roles were reversed.
But also my previous relationship of which he is aware, where my partner made me pay for absolutely everything, charging me mileage for trips to the supermarket, I paid all the bills, house move costs, food, clothing, nights/days out, Internet, wear and tear on his car components, unexpetced journey detours, petrol, presents for his family.. I do mean literally everything.
He didn't pay a penny towards the new baby necessities (and still doesn't offer money towards his two young children). He wouldn't even allow his then toddler to have an ice cream or go on fairground rides unless I paid for them (well I wasn't allowed to buy an nice cream because "you can buy a litre of ice cream for £4 so why pay £2 for a single cone") etc. There were DV issues and the first time he called me a C* in front of everyone else in the queue at a steam rally fair for arguing the case for an ice cream cone for our toddler because it was a day out and it was supposed to be fun, well I never bothered insisting on that again obviously :/ Yet he asked for money for his beer and roll at the event...
He didn't work and I was temping not earning regulalrly, so I obviously accrued utility bill debts during my time with him because I couldn't afford to support the two of us on temping wages, which have followed me in the years since, to the point of my applying for bankruptcy this year.
With my new man, I do always offer to pay for things even if he wont let me, and the early days when we were dating I did insist a few times cinema trips, etc, he didn't know then that my paying for the cinema was using up my last £20 in the bank! But it is a bizarre feeling for someone to be so opposite to what Iused to for so many years.
When my youngest starts school this September Icanhopefully find work and the situation won't continue, I will be in a financial situation to go halves more often.
But I think it's down to his natural character anyway. I certainly think if I was in his situation I'd be the same. I never resented the way my ex made me pay for everything - I never questioned it at the time because I was blindly in love. If my partner is clearly in a poor financial state I wouldn't think twice about paying for them, it's only money.
(I hope) he knows how appreciative and grateful I am, but whilst I do feel humbled by his generosity, I do know that the situation is temporary and that I can eventually pay my own way more often when I start work.
The phrase 'gold digger' is a horrible one and I wouldn't even bring it into a conversation let alone my conscious thoughts. Men aren't stupid and in those scenarios I'm sure they can recognise that quite quickly- any new girlfriend who is constantly asking for designer handbags and shoes or whatever it is gold diggers do, is not going to be a keeper. I expect she would be treated with the same disrespect eventually that she is bestowing on her. You don't need to worry that he is thinking this about younbecause you are not displaying those temdemcies. When you say he sometimes let's you pay, even though he knows its financially difficult for you, it's probably because he understands you need to have that sense of control.
The London trip you plan. Well, the only way forward with that is to be completely straight with him about your finances, I'd say.
Explain that you can contribute to an affordable degree, but it probably won't match his contribution, simply because you're both in very different financial circumstances. There's no other way round this issue really than to talk about it.