My husband and I are like this. It’s not an “if I let him” or “of he lets me”. We discuss things and weigh the pros and cons. I’m his wife not his mom. He can do whatever he wants, go wherever he wants. Get anything he wants, as long as we have money to eat on. It’s the same with me (harder for me to go anywhere I want though since I don’t drive but you get the point) we are adults and we know how to be responsible with our wants.
That being said, if it’s ever a big decision, we do talk about it. It’s not like I’m going “Hey baby,I just bought a 3,000$ tank, we have to find a spot for it”.