L.C.
Maybe because I grew up learning that family is not just flesh, but if they do not care about you and your child to forgo the drugs until after you leave, they are not really family. Let your child celebrate Easter and spring in a positive environment- go out to the park, to the children's museum, etc. And you never know - you not allowing your son to see this may just be the motivation they need to get their acts together.
However it goes, may your holiday be happy.