Arrrgle. That must be hard. Yeah - undermine it however you can get it under the radar. I think the thing that aunts and uncles are best for is to show up for the 'you need a village to raise a child' and nurture any vocations if they need back up - say the lad suddenly wants to be a ballet-dance, or the lass wants to be a scientist, you can be the one that backs them up and buys them the stuff they actually want for that interest. You can help validate their choices in life if they find themselves being invalidated by their parents - and that goes for anything not just this issue.