Bookbent discussion

Recently I read the "Fever Crumb" series from the teen sci fi section. In the third book... not to give too much away... she falls in love with another girl (after having been enamored with a boy in book 2, and no previous hint bisexuality. It was a pretty good surprise and I liked how the book wasn't a "gay" book - it just had a normal character who happened to fall for a girl, rather than a "token" or two-dimensional character whose whole schtick was their gayness. Are there other books you've read that aren't "issue" books that unexpectedly have a bit of realistic diversity in them?