I am genuinely grateful for everyone's views, and thank you for sharing your thoughts with me. However, please remember that giving advice is a one-sided street where the receiver may choose not to follow it.
One of the main reasons why I can sort of see where he was coming from is that when my exh and I separated, my life was an absolute mess. And I ashamed to say that instead of giving myself time and focusing on sorting myself out, I embarked on a relationship with a very nice man. There was absolutely no way that I would have shared the true state of my personal life with him straight away. Some things he already knew as we had known each other for a long time, whereas others, especially the financial side of things, no way. I was too afraid that he would think less of me. I didn't use him, I didn't take a penny from him but he was potentially going to marry me without knowing the extent of it all. I've matured and my life is as uncomplicated as it could be, apart from DP, of course!
Likewise, DP doesn't know that when I got offered a high paying job last year, that I didn't turn it down. They turned me down because even after all this time, my credit history still isn't as up to scratch as it could me. I am ashamed of it but I don't need help, and I most certainly don't need anyone's money. But do I want DP to know that? Maybe he should know as although my last Experian report gave me star rating (?!?!), it would impact my (or our ability) of taking out a mortgage together (if I didn't already have one).
So is that different from him being in denial about having been a lousy parent to his older children (both adults, grew up in another country)? He's always been very defensive about having provided for them financially, trying to justify to himself that it made up for him not being there. I am not having any more children, btw. He thinks, and rightly so, that he will be judged for it and that it'll scare any half-decent person off. A guy with 'God knows how many children' dotted around - hey, what a catch! ;-)
But based on my own personal experience, people can take control of their circumstances (as I've done with my own). He's got nothing to gain and he's a very generous guy, but he's made plenty of choices along the way which he obviously thinks put him in a disadvantageous position. Emotional immaturity and a good dose of narcissism? Yes, most likely. It doesn't necessarily make him a bad person but there is definitely a big, red flag waving there somewhere...