You're not understanding that both your kids are adult men now. Not your "children" any more.

You'll have a better relationship with them if you figure that out and stop trying to parent these adult middle aged men, and start treating them as your equals. If you wouldn't try say something to a coworker because it comes off as parentification and patronizing, rethink why you're saying it to these adults. Think about where you were in life when you were in your 30's, and if you needed your parents to make your decisions for you at that point. (And god I hope the answer to that is no.)

So when you're talking about a middle aged man planning his wedding reception, that he's paying for himself, unless you are the hired wedding planner, any sentence that starts with "In terms of the wedding receiption we were thinking ..." makes YTA.