Albatross Dreamer

That seems to be a good way to go about it. The only thing that may or may not have made sense was framing it slightly different. Instead of “don’t do it again or I’ll report you” perhaps something such as “I’ve seen you play and you’re too good of a player to be doing that”. Basically try to encourage the kid and appeal to a positive reason not to do it. To me would depend on the level of play, age of kids, etc as there’s not necessarily anything wrong with what you said as well.

How do you know he’s not already? Seems you’re filling in hypotheticals off what he didn’t say and assuming he’s looking at things in a “self-centered” way