I think it's going to be tough to have this conversation, but not having it will mean disaster.
Friend,
I'm very concerned about how L is eating. Both his regular diet and his snacking are out of control. The way he's eating isn't acceptable for anyone, never mind someone with diabetes. Because I've become something of a regular caregiver for L, I'd like to talk about how we can address this concern. Without addressing this issue, I'm concerned that L may have a medical emergency. If things do not improve, then I will need to stop watching L. I don't want to do this, as both our sons love getting together.
From now on there will need to be some new house rules.
1. L must eat what the rest of us are eating at meal times, except as it would impact his diabetes. There will be no more special meals.
2. I will have healthy snacks available in a special drawer in the fridge and a bin in the pantry (or tag them with green dots). L may help himself to these as he'd like. I will keep a few special treats in the house, but L must ask before taking these.
3. L must test his blood sugar and report it to me according to his treatment plan.
I understand that L is a teenager, and that he's going through a lot right now, but I can no longer sit by and watch him destroy his health, and I can no longer feel the anxiety of not knowing when he will have a medical emergency. I hope we can work this out together.
I would argue he gets one warning. The second time she needs to arrange someone to come get him within an hour. After that, take a week off of visits, then two weeks, etc.