Any grammatical way you look at that title it works (after all, it "is" "his" back). Which brings me to something else: I've decided to call our male friend "Fred." "Fred" was supposed to be replaced by "Sally" today. But apparently something came up. So we did a side of "Fred" we've never seen before: the backside. I reckon Mom would've liked this one. As interesting as it is to sketch good ol' "Fred," though, I'm looking forward to softer-fleshed "Sally." She should be showing up in the next couple of weeks. Enjoy.