How do you stop house guest from damaging your speakers?

Over the years I have had many adult guest coming to my house and curious about my speakers though I never mention to them I’m an audiophile. Most of the time they will lean close to the speaker, looking at the driver, maybe occasionally touching the cabinet or knocking on the cabinet. But in other times I’ve had guest touching drivers gently as well and I usually just tell them to stop to prevent them from damaging the driver when I see them doing that.

Yesterday I had a little sit down with a few guests and one of them wanted to play my Blade 2. Out of nowhere, while the music is playing he stood up and walked to the speaker and knocked on the side driver woofer and asked “are these speakers too?” It was probably 3 or 4 consecutive hard knock on the woofer while the woofer is playing, and you guys can already imagine my facial expression. I don’t want to blame the guest as the blade’s woofer doesn’t look like regular woofer and I can’t expect guests to have knowledge of how not to damage speakers, but man, that really hurts when I saw that happen.

I inspected the driver afterward and it seems like all is good and the driver survived. I don’t remember if I heard distortion while the music is playing but to my knowledge this would easily fall into the abuse category for an audiophile.

I’m wondering, do I attach a label to say do not touch on those drivers? Do I tell guests not to physically touch the speakers?