Jessica Simpson is opening up, quite literally while flaunting her killer thigh gap. The 40-year-old actress, singer, and "Open Book" author is currently big-time promoting the paperback edition of her 2020-released memoir, with the book now coming complete with a brand new journal segment on her divorce from Nick Lachey. Jessica, who yesterday appeared on both "Good Morning America" and "Live! With Kelly and Ryan," took to Instagram last night with stunning promo shots showing her latest "Open Book Looks." Check them out below.