Sounds like the saddle is probably the main problem! Thanks for the input!

I'll swap out the Bontrager for my old Terry Butterfly and try another long ride in the LG shorts (as soon as my butt recovers from yesterday's 'adventure'.) I'm not in love with my Terry but I've never hurt on it the way I did on the Bontrager! I've ridden up to 75 miles on the Terry and felt "ok" at the end of the ride.