C.C.
You are not overreacting at all. Since your brother brought this to your husband, I think that means that your brother is reaching out to the stable adults in his life for help. (If he were happy about getting a fake ID and going to strip clubs, he wouldn't have said anything.) He trusts you to help him, and that's a good thing. You and your husband need to tell your cousin and father in no uncertain terms that they will not be visiting with your brother unchaperoned anymore. It is definitely not ok to take a 16 year old to a strip club, nor is it ok to give a kid with a family history of alcoholism a fake ID!! With those kind of friends, who needs enemies?!