For example, if I say I don't like it when DH drinks and ask him not to, I'll be told on here that's controlling.
But if I say nothing and he goes out drinking with varying degrees of consequences for him/us I'll be told I shouldn't stand for it.
The same with hobbies or unpleasant friends, a particularly close relationship with MiL (all just examples, not the same man btw), asking him not to is controlling (according to MNetters) but "letting" him is something that shouldn't be stood for.