When do the lies become unforgivable?

Bf of 6 years has lied about his finances in past to make it sound better than it is (he racked up a lot of credit card debt he couldn’t afford). Because of this I never lived with him. We do love each other and have chemistry.
He is finally getting his finances back on track after much effort on my part of helping him budget etc. and him getting a modest cash gift from family. However I find out that his elderly mother is in credit card debt up to her ears and he is working it out through lawyers to close her account (he handles her affairs as her POA). Trouble is he used that account from time to time when he claims he was short on cash including paying car insurance (every month including up to January) but the REAL issue for me is when I asked a month ago he said he only used her card for gas from time to time (he now says he told me car insurance but I don’t recall that at all and then he said he forgot it was an automatic charge to her account). What made me ask was I noticed he used her card to pay for an expensive dinner recently and I got really upset so he put his own money in her account to pay it.
Now that I "caught" him, he tells me today that he finalized closing her 1 account she can't afford (and settle for some dollar amount), he is paying on her other account (a healthy amount each month) and he contacted his bank to make sure his car insurance is paid from HIS account starting next month.
I suppose now I need to decide if all these lies should be excused since he wants to move in now? Is it worth the risk even though I really love him and know that he is paying his own bills currently (given the cash gift and help from me)? Is he entitled to another chance???

It's up to you to decide whether something is forgivable or not. To me financial lies are not forgivable.

I am with madotnw. Lies like this, in my book personally, are not forgivable. Especially given the nature of it. Not to mention... you claim he's finally getting his finances in order..... but in the same breath you explain that is because of A CASH GIFT from his family. In other words.... he's not getting his finances in order at all. His family is by bailing him out.

And, Hell, anybody can get stuck in a rut like that. It can happen to any of us. Sometimes, a little help from your loved ones can help you finally dig yourself out of that hole. I HOPE that is the case with him, but it is just as likely that he'll just wind up digging himself into another hole. It's just as likely that his family's bailout will all be for nothing because he'll be right back in debt all over again in no time. I hope that isn't the case, but that happens all the time with people who are bad with finances.

And, honestly, when it comes right down to it... If I were in your situation, it isn't so much the financial issues that are the big problem (they are a problem, but on their own maybe not as big a problem). It is the lying that is the problem.

Personally, If I were you, this would be enough for me to take my leave of the situation. But, you are not me. You are also closer to the situation. Maybe he truly IS making efforts to better the situation. Maybe his recent efforts are not just for show/just to appease you. You would know that better than I, so if you honestly feel he deserves the chance to prove himself then you'd not be wrong to give him that chance. I'm just saying you'd also not be wrong if you'd just reach the conclusion of enough is enough.

Good luck to you either way.

To answer your thread title.

When another who loves you betrays your trust and won't change and is selfish.