As we told you in “Life Does Go On After Sex With Chelsea Clinton” in August, the former first daughter’s ex-very serious bf Ian Klaus has written a new book called Elvis is Titanic. Now, WWD reports, Chelsea is supporting the tome, and has even asked daddy Bill to host a book party this week to help Klaus out with sales. ”[A]lthough the notion of ex-girlfriend’s father as book party host certainly isn’t customary, a spokeswoman for Knopf, the book’s publisher, added that Chelsea and her friends will be in attendance,” according to the magazine. ”In fact, Klaus dedicated the book to Chelsea.” What a guy!