Here is a bit of advice for you young moms. You will be tempted at some point to use this argument. Your youngish kid (most likely teenager) will want to do something to themselves that you do not like. Tattoo, weird hair, piercing... etc... you will think to say, "When you pay your own way, pay your own bills then you can do what you want. Until then, NO."
This is what can happen... Matt, he works hard, pays his own way, is 21... but as a Mom, I really wish I could still say NO.
So my advice, don't give them that little speach, always hold onto VETO rights. Yes, I know it will still probably happen, but at least you can be grumpy about it.