How dare MIL buy her son a present

[Flojobunny]

I know I'm being unreasonable, but it's too late. I've had my strop. I'm now upstairs unsure how to proceed.
Bit of background, DP is in debt, he sold his IPhone 5 and motorbike to clear some debts and pay his share of the bills. He's crap with money.
He told me he'd got me something special for Xmas so I then panicked at my paltry offerings and ran out on Xmas eve and spent lots more. Then Xmas day came and he had bought me a couple of cheap tat and said he intended to get something special but didn't know what, so didn't.
Last night he was moaning that his older phone was too slow so now MIL (who is staying and gave him Xmas present last week) bought him a new phone and I said (to DP, not MIL) "but that's not fair, I have nothing, and the sacrifice you made for us by selling your phone means nothing ".
Damn it, now I look like the spoilt brat not DP.
I'm now hiding upstairs, god knows what he's told MIL. I was awful wasn't I?

If she wants to spoil him I guess that's up to her but it doesn't look like she's taught him the meaning of money full stop.
How did he get in dept?

No, you weren't awful.

This guy is milking both you and his mother for every penny he can get out of you.

He LIED to you about what he got you for Christmas deliberately so you would get him a decent present.

He's not crap with money. He's brilliant at getting other people to pay his share and he's not going to stop now.

I suggest you proceed by financially separating yourself entirely from this man before he takes you for even more.

What Join said

I bet his Mum doesn't know about the debt and thought she was just being kind by getting him a phone he wanted. The sacrifice he made didn't mean nothing, he didn't know his mum would buy him a new phone.

Thanks for the advice. I fully intend to keep it seperate.