apron string
figurative That which binds a woman to her husband or child. The phrase likely alludes to "apron-string tenure," a 17th century law by which a husband could control his wife's property (and her family's) during her lifetime. Often used in the phrase "tied to (one's) apron string(s)." I can't believe how much Michael is tied to his mother's apron string! That's the only explanation for him still living at home at age 40!