Hey @DavidThomson,
I can't imagine how stressed you must be feeling right now. It's always concerning when our children engage in risky behaviour, but even more so when they are putting themselves in such danger at such a young age. It makes a lot of sense that you're also struggling with what to do in this situation.
In terms of punishment, it's really good your son is feeling remorseful, and that he understands how serious his actions were. However, the fact that his actions broke your trust in him are valid, and should also have space. In terms of type of punishment, it may be a good idea to frame it around this sense of broken trust, and the fact that a consequence of breaking it, is to earn it back. What could work in terms of punishment is putting in some really strong boundaries (perhaps like an initial grounding, or very early curfew, or increased adult supervision), and then as he does earn back your trust, these boundaries can gradually relax. This may give him a greater sense of agency over his actions - not only encouraging him to take responsibility for what he had done in the past, but also what he can do to atone for it.
In terms of addressing the situation with the other boy, it might be a good idea to reflect on what you would do if you were in the other parent's shoes. I'm sure if the situation had been reversed, you would want to know that your son had taken LSD. It might also be helpful to have a "team" chat with the other boys parents, and together you can come up with a solution.
It might also be a good idea to give ParentLine a coll as they are experienced counsellors, who have a lot of experience in supporting parents with a number of issues. I hope this helps!
