Guardsman18 Your story is very similar to an issue that I had with a 'friend' a few years ago. She actually slept with my boyfriend when we were teenagers, my boyfriend and I split up and she dated him for 2 years, in which time she got pregnant, had an abortion and her Mother kicked her out the house as she found out and was strongly pro life. She failed her A levels, didn't ever go to Uni, got into a lot of debt and ruined her credit rating and has worked in very low paid jobs ever since. After a few years of not talking to her, I realised she'd actually done me a favour as my ex was an arsehole and she apologised saying she was young and an idiot and realised her mistake...
(Context is relevant, I think). I went to Uni, got a graduate job and rose through the ranks quite quickly and kept doubling my salary.
Every time we met - I paid... all the time. When we met at coffee shops, she would deliberately hang back and my politenes would get the better of me and I'd ask 'What do you want?'
Due to her having a bad credit rating, she only had a cash card and never had any cash on her when we went for dinner, so she'd end up promising to pay me back and never did - and I was too weak to ever ask for the money back.
This went on for YEARS and YEARS.... I never challenged and she just kept on taking the piss.
One year, I mentioned I was going to see Take That with my sister and she said she'd like to go too and that she'd pay me for the ticket - like a mug, I agreed and bought 3 tickets. I did actually ask for the money and she said she was broke but she'd give it to me next month.... then I saw that she'd posted on FB that she had felt 'down' and had gone for some 'shopping therapy' and posted pictures of the new books, shoes and clothes she'd bought herself....
So, next month, I asked for the money again and she said she was really sorry but her car needed work so she wouldn't be able to pay me, so I said 'No worries, Friend X wants to come and is happy to pay, so she's happy to buy the ticket' (Take that was 2 weeks away so I couldn't / didn't want to wait for another month) She said if I was being 'like that' she'd bring the money the next time she saw me....
She did... she came to Take That and was in such a FOUL MOOD, as if I had massively inconvenienced her, as if I was such a horrible person as I had the audacity to ask for the money back.... So after that, I backed off.... She messaged me asking what was wrong and I told her - I was sick of her always letting me pay for things and promising me money back and never actually giving it to me - She actually apologised and admitted that she'd taken the piss.
So... we agreed to meet up, go for dinner - I deliberately took cash and kept my card at home (actually hid it in my sock, but hey....) and we had a nice dinner, it then came to the bill - She made a token effort of looking in her purse to say to me 'I'm SO sorry, but I totally forgot that I used cash to pay for my bus fair and bought a coffee, I don't have enough - Can you cover and I'll pay you straight back?' I said 'No, sorry... I lost my card, I only have cash, see?'
The look on her face.
And then she said 'What do you expect me to do?' It was at that moment I realised that she never had any intention of changing, that she just continued to want to take the piss and our friendship was over.
(And no, I didn't pay for her... she had to leave her driving licence in the restaurant, go to a cash machine... take out cash - which transpires she had no money in her account, so had to phone her parents to transfer some... so she could pay her half!)