He's a grown ass man, with a fiancée, being treated and acting like a child. Not to mention the OP's mother-in-law criticizes everything about her, which is not fair. That is not healthy, what is healthy is to split of a from mommy and daddy, at least a little bit, and have you're OWN LIFE. She shouldn't be buying him clothes, that's his job. She shouldn't be calling on her grown son, who has his own responsibilities, to do stuff for her around the house. She can do that HERSELF, or get HER OWN HUSBAND, to do it. He needs to grow up and make his own life and his fiancée's life a priority, not his mother's.

Buying him clothes isn't bad. If it's all the time then it's bad. But every once in a while doesn't sound so bad