apron strings, tied to someone's

dependent/overly dependent on, clingy, immature, timid, childish, pampered, protected, can't make a move without, no mind of one's own. Hugh Rawson (Wicked Words) defines the expression as being "unduly subject to one's wife or mother" and says it dates back to at least the 16th century when the legal term "apron-string hold/tenure" referred to tenure of an estate by virtue of one's wife or during her lifetime only. See also henpeck/henpecked.