While not Spanish-language, Benjamin Braddock in The Graduate is a proto-abotonado. He is buttoned not to his literal mother, but to the maternalistic expectations of an entire generation (Mrs. Robinson’s world). However, when he falls for Elaine, the dynamic inverts. Elaine’s mother is the true "abotonada" villain. The famous ending—the bus, the panic, the two of them sitting in silent dread—is the perfect metaphor for escaping the button. They ran, but the buttons are still attached by threads of guilt.
In many cultures, the relationship with a mother is the primary blueprint for love. A "buttoned-up" connection implies a high level of intimacy, shared secrets, and daily involvement.