61: On A Bus: (free use world, sexually permissive future, post apocalypse wasteland) 62: In a temple. (Fertility Rite, desecrating a rival god's fane by breaking their repressive taboos, or consecration of a new temple to a god/goddess of sexuality.) 63: Inside your own head. (Cyberpunk mindscape videogame, magical shared dream, and everyone who visits the main site!)
64: Back of a truck. (Bonus points if it's moving.) 65: In a Limo (After prom or the wedding.) 66: In the attic.
67: In a wind tunnel (for endurance training) 68: A massage table (one at home or one at a less than reputable establishment) 69: A MMA ring (after a hard won or 'hard' lost fight) (Someone should make this into a story and write a chapter for each of these )
So Chapter 1- Taking it up the ass in the attic. Chapter 2- On the beach with my bitch. Chapter 3- the cabin and the cunt. Etc...
Well we've broken 69, so let's break the boundary of the afterlife. 70 - heaven (self explanatory) 71 - hell (self explanatory) 72 - purgatory (there's a clear theme here)