https://imgur.com/a/FgZlc

What's annoying is he was one of those 'Can I join someones island' and also asked for 'some cobble or something'
I was feeling generous and told him I could give him some cobble, so while I was gathering cobble I let him look around the public area of my island. (The section he no-clipped to was sealed up because it's incomplete and I want it to be a surprise)
Then when I asked him how he saw in he was like 'lol not telling'
So I was like fine "No generosity for you" and booted him from my island. Where I explained to him why, and then the screen cap I took was him admitting to using no-clip.