tied to (someone's) apron strings

Translations
привязан к фартуку (кого-то)
He is still tied to his mother's apron strings, even at the age of thirty.
Он все еще привязан к фартуку своей матери, даже в тридцать лет.
Definitions
Being overly dependent on someone, typically a parent or caregiver, to the extent that it limits one's independence or ability to make decisions.