An update: DS spoke to me late last night. He tells me his dad has given him £100 for his birthday and returned the clothes he bought him (super helpful when he actually needs a few new clothes). His grandparents from his dads side, who are amongst the poorest pensioners I've known, have given him £200 (given for his entire life they have given him £10 at birthday and christmas, this is an interesting revelation). He has budgeted £70 a month to pay back after that.
He doesn't know how he will manage to pay for lessons, or any of the other things his wages should be going towards (plan was save half, spend half on driving lessons and any gig tickets or expensive clothing he wants).
He hasn't even got any hours this week as no shifts are going.
He now reckons he will be finished college in May as he has finished all his course work, and the other kids will only be going to do their maths/english gcse resits, which he doesn't as he passed them.
He thinks he can find another job.
Me? I think he's unrealistic, and telling some untruths. But what can I realistically do? He thinks he has a plan. I think his plan is shoddily built. But you try telling a 16 year old that!
His driving lessons are important. He is studying engineering. He is unlikely to go down the uni route, therefore meaning driving is an even bigger life skill to give him work opportunities. I've worked hard to set up the opportunity for him to drive, got a car arranged and insurance for the first year covered by a savings policy that matures next year. I don't want him to blow that opportunity for a bloody holiday in Benidorm 
.
I will speak to the other parent later this week, to ask a list of questions ie. Hotel and flight details, room arrangements, cancellation arrangements. I will also be telling her that DS will pay it to her at the start of the holiday (as I would worry he pays it and then doesn't go for some reason out of hia control, and I can't let.him throw the money away).
Someone asked why I haven't spoken to them before - I've had no need to. Relationship has bobbed along nicely, she comes over once or twice a week, he walks her back home around 8pm.
The reason I contacted them was because I found her in his bed on sunday morning. I assumed he had snuck her in against my express wishes (he asked the day before if she can sleep over on his birthday, but I have said no as I have 2 young kids, one with additional needs who doesn't sleep. Night guests aren't welcome for the unsettling nature for my other child). As it was, it turned out he had let her in at 9am and not told anyone. Confirmed by the friends mum who she had stayed at the previous night. Anyway, this is how the holiday conversation came about. The mum also told me that when my son had stayed at hers, she had made sure he was on the sofa.
Now, this was news to me. DS doesn't stay out often, but he has never asked to stay out at hers (he does ask if he can stay out, although I've never told him he needs to). Regardless of how you feel about 16 year olds staying at their boyfriend or girlfriends, at 16 I would not assume the other parents would be happy with those arrangements. So again, she has permitted my DS to stay over without knowing that I am happy with that level of trust. As it is, I am mostly okay with it. But she made that assumption. I would always check the girlfriend/boyfriends parents knew and were okay with it.
So basically, I now feel like she is making
decisions and having parental input in my DS's life, with no regard for his actual parents. I just wouldn't do that!
And yes, I was a 16 year old who left home too, pregnant (with him!). I'm well aware of the predicaments of being 16/17. Not a child. Not an adult. My mum gave up on me. I don't want to be like that. I want to help him make good choices in his life where I can.