'Ideal Marriage' Book Returned 54 Years Late

— -- It is not often that a library gets an overdue book 54 years later, nor is it often that the book is sent back anonymously from a “shocked in-law.”

That's what happened, however, when the New York Public Library received a copy of “Ideal Marriage,” a 200-plus page book on sex -- along with an apology note.

“We found this book amongst my late brother-in-law's things. Funny thing is the book didn't support his efforts with his first (and only) marriage... it failed! No wonder he hid the book! So sorry!!,” read the note, signed, “A shocked in-law.”

Texas Man Booked For Not Returning a Library Book

Library Book Returned 55 Years Late

Rare Book Returned to Library 78 Years Late

The book, authored by Th.H. van de Velde, a Dutch doctor, was due to the Mid-Manhattan Library on Aug. 17, 1959, but was just received at the library in May of last year.

The library’s managing librarian, Billy Parrot, first revealed to the public the book’s long-awaited arrival in a post last week on the library’s website.

“I imagine the patron feeling so guilty about the lateness that weeks turned into months, months into years, and years into decades,” Parrot wrote in the post titled, "Better Late Than Never."

“In addition to the guilt associated with overdue fines the patron also had to bear the humiliation of returning such a lurid book!,” he continued, describing the book as, “a very wordy and very scientific instruction manual for sexual activity written in 1926.”

Reviews of "Ideal Marriage" on Amazon.com describe the tome as "highly useful" and "Just as up to date today as when it first came out." One reviewer said they give the book as a gift to newlyweds.

"Gives detailed instructions for a mutually fulfilling love life, which I began to apply 70 years ago. Learn from it," wrote another reviewer.

Parrot notes that out of all the words and descriptions in the book, the only line that was underlined dealt with, “men who ‘only care to relieve their own tensions and care nothing for their wives as an individual or mate.’”

The library’s current late fee for hardcover books, as listed on its website, is 25 cents per day.

For a book that’s 54 years over due, the charge would round out to $4,927.50.