"What ds and I talk about has nothing to do with you" was I out of order?

[Crystaloid]

Dp's 17 year old son yesterday sent dp a text message saying more or less "since you promised to buy me a car, can you make it a motorbike? I've seen the one I want but I need to know how much you are willing to spend please".

This comes after weeks of him ditching his father on a weekend in favour of his girlfriend and this weekend ditching the premiership football match his father had paid for tickets for at last minute because he had better things to do. I knew NOTHING about dp promising him a car never mind buying him a motorbike and at the moment we are budgeting like crazy trying to remain afloat after just buying a house. We both work, dp pays a lot of maintenance and we have joint finances so needless to say thus message put the fear of god into me. I waiting until gone midnight and do never mentioned it to me so once in bed I tactfully said "you're not planning any major financial commitments without talking to me are you?" He knew what I was getting at and blew up saying that was between him and his son and nothing to do with me!!! Aibu in thinking its got everything to do with me?? Anyway he said he's going to tell him "no" but it's in the back of my head that he will be talked around and that will see us firmly up shit creek without a financial pedal. Am I wrong to "interfere" in this?

Oh and he accused me of shit stirring. Saying his relationship with his son is already fragile and I'm doing my best to stir it up further. He accused me of not loving his kids or his relationship with them and says I don't understand anything.

YANBU. I think the ditching thing is fairly normal teenage behaviour though, as an aside.

Joint huge purchases that you can't afford should be discussed, definitely.

Well depending on the circumstances I might allow that he has a right to be angry with you for looking at his text messages.

But otherwise since a car/motorbike is a MAJOR expense, and presuming you have joint finances and you would in fact be part-paying for this huge luxury...I really don't see how he could say it's nothing to do with you.

I think I remember your previous posts...sounds really frustrating.

Op has he by any chance got a slightly younger son? Nd have you name changed?

I agree MAJOR financial purchases need to be discussed together.

Is he your DP only child? Will younger children expect the same when they reach 17? We have tried to give all our kids the same (e.g 2 of them have been on trips abroad to Spain/France, 3rd one is going next year)

I think Ellie may have this...

I thought the same as Ellie.

OP, I mean it in the nicest way, but if you are who we think you are, this is NEVER going to change or get better... Why do you stay?