Is it fine if I wrap a fake present for my kids?
Why would you trick your kids with a fake present?
It's a present for them. They are kids. They will not know the difference
It's okay do something for your kids, even as a joke. They'll appreciate that you thought about them and will remember it.
I love to have fun with my children!
Having fun with your kids and even being silly with them sometimes will make them feel more open to talking to you about serious issues they might have in their lives later.