It's often hard to find, surprisingly enough, because so much science concerning sex and sexuality is shut down because of ridiculous politics before it can be done. In North America, anyway.
In a historical context, "The Greeks And Greek Love" by James Davidson is a fantastic (if not exactly sprightly) and clear-minded reappraisal of same-sex attraction in classical Greece that very persuasively does away with the idea that filthy old Greek men made a habit of molesting little boys, and explores what the evidence shows male-male attraction actually looked like, without trying to transpose modern concepts of sexuality on a culture that is exclusively not modern. In fact, it argues quite well that transposing one's own ideas of sex and sexuality on another culture is exactly what got us our skewed idea of classical Greek sexuality to begin with (read: don't trust Victorian translations). A great read.