There’s a book, Pica, and it’s a very good one. It’s called “The Sexuality of Christ in Renaissance Art and in Modern Oblivion” and it’s by a mad genius art historian (still active) called Leo Steinberg.

I think you’ll find even the book’s table of contents very exciting:

http://www.press.uchicago.edu/cgi-bin/hfs.cgi/00/13085.ctl