I agree with you! I'll share my experience with them and hope they understand they can talk to me about it without judgment. If you allow it, you can always have a conversation about it. If you prohibit it, they'll just end up doing it behind your back and it'll be too late when you know.

Also, I'll never tell them not to do it, but ask them why they think they're doing it. I think it's important to understand what void it fills or why and how you think it helps you.