Worst dad in the world!

[WkdSM]

Long story short - DSS1 is 20, his mum forced him to leave home a year ago and since then he has been working hard, paying rent, learning to budget and has now applied to uni as realises he needs more qualifications to get the type of job he wants. DH and I are taking him and his GF away for a week so we can spend some time together and they could not afford to go away.
SS2 is 17, lived with us for 3 years (he wanted to as did not get on with mum and his SD) but is back with his mum doing A levels. We pay nearly £800 a month via CSA (original court order maintenance stopped at 17 but CSA over rode that - unfair but there you go). He has stolen from us, lied to us, and done some fairly awful things and tbh I can't stand him. He failed his AS exams earlier this year and we think he may crash out of school.
He texted us to say he wanted to buy a car and take driving lessons but the insurance would be £4k (as he would be insured as a learner driver). Can he have the money. DH said 'no' - we are paying a lot for his maintenance, we can't afford to just shell out £4k and if he wants a car he needs to be able to run it himself. Maybe he should take lessons and wait to buy a car until he passes his test.
A huge diatribe came back about how terrible it was that we were taking his brother on holiday and not him (he went on a couple of hols DSS1 did not go on when he lived with us and quite frankly I would not relish a week with him), how DH is my lapdog, and how he only parents by cheque book. (Funny how he likes that cheque book and gets angry when he does not have access to it). It is not about the money he says, but the principle - not sure what principle but there you go.
So - DH is the worst Dad in the world.
Would you give him the money (as even if we said it was a loan he would never repay it) just to keep the peace or would you stand firm?

Personally id say stand your ground and dont give in. From what you've said his issue is with the money as his dad has said 'No'.

Why does he need a car whilst learning to drive? Many people dont have that luxury If his parents we're still together would either of them even consider paying 4K for insurance so he has a car to drive prior to passing his test?

I wouldn't give the money to my DD, DBDs or even myself ( I am currently learning to drive)- What utter nonsense.

I wouldn't give in - clear emotional blackmail here.

Let him start his lessons and offer to pay for some of them. Handing him 4K is plain madness and would confirm that your DH is guilt-parenting him.

Stand firm.

I was a bit confused about the csa - you don't mean you were paying his mum while DSS lived with you, surely?

Thanks for the feedback ladies.
We did not pay his mum while he was living with us - and she did not pay us a penny. We should have asked for some but we were trying to encourage SS2 to rebuild his relationship with her as they did not speak for 8 months after he moved in with us.
He seems to think we are a cash point and gets really abusive when we say 'no'.
His birthday money this year was meant to pay for some lessons - but he has only just applied for a provisional license now (b'day at beginning of the year).
This is not as bad as some of the issues we have had with him, but DH is saying that he really is starting not to like the person SS2 is rapidly becoming. I know that a lot of behaviour is down to upbringing, and we must take some of the responsibilty for it, but his mum is generally the same - OKish while you do what she wants but as soon as you don't / can't she goes into a complete fanny - fit.
I would also be worried about him having a car before he gets a full license as I would not trust him not to drive it on his own.

No way .... tell him to get some manners, and a bike, if he wants transport. Sounds really entitled.

If you give in now, this'll only be the start of it. The insurance if and when he passes as a 17/18/19 year old male (in particular) will still be horrendous - who'll pay for that ?

The lucky kids who get lessons/cars/insurance etc from their parents are just that - very very lucky. Most kids don't ... and you'd hope that those who do appreciate it, don't take it for granted and would have been reasonably pleasant people. Doesn't sound like your SS fits the bill.