I don't know if any of you read the "My Married Life" blog on here, but if not, you should read this one. http://ideas.thenest.com/love-and-sex-advice/my-married-life/blogs/my-married-life-joy-of-sex.aspx
So anyways, the same kinda thing happened to me when I was younger. I found that book, and my dad's Playboys in the basement :-X Only in the past year did I find out where the book came from.
I guess, after my parents got married my dad's dad sent my parents a copy of that book. Not even as a joke. But like a "hi, you're married now, here's what to do" kind of thing. (Why on earth he would do that I have no idea) This sparked the biggest fight my parents have ever had. My mom was furious that he would do that. And my dad thought it was no big deal. I guess the fight lasted like, a week.
So when DH and I got married we kept joking about getting a book in the mail. I would not be surprised at all if my dad sent us one. But at least I would know he was joking. Lol
Re: "Joy of Sex" (family story)
We received this as a wedding gift...
Seriously though, we were opening presents Monday after the wedding with our family and this book was wrapped from an unidentified giver. We later found out that it was from one of DH's friends and mostly intended as a joke. If you get the updated version and ignore the pictures, the book has some good points