Rachel, you're definitely between a rock and a hard place.

If you want to protect yourself, he may feel insulted. If you make him feel good, by trusting him, you could suffer badly, from his (unintentional) carelessness.

What about telling him straight out, that in order for you to come, that you would have to bring your own cookware, and your own g-f ingredients, your own paper tablecloths, your own silverware, etc., &/or, you would have to bring already prepared dishes, etc.

Or, could you tell him that this time, you want to bring your own safe food (pre-cooked, etc.), but, that sometime you'd be happy to show him how you make gluten-free dishes, and how you really have to have a totally gluten-free home, in order to stay well.

Can you ask him to try to go totally gluten-free for a month?

This is a tough one! No easy answers I think. Good luck!

Or, another idea I just thought of: Can you invite him and the others to eat at a gluten-free restaurant, (if there are any in your area) instead of cooking in?

Carol
http://cantbreathesuspectvcd.com