Also, think critically about the people who promote these views. Most of them aren't very smart (in the sense that a tenured professor with awards can still be an idiot), or have a vested interest in promoting these views (typically racial).
Here's the first Google hit I could find disproving your joke. Someone else can find a blog post where a lesbian buys her daughter a firetruck and the girl begins to nurse the firetruck.
The world evolves in a certain way for a reason. Do you think this is the first era in which people thought that everyone might be equal? This is the first era in which we've had the luxury to attempt the experiment. The results are in: people aren't equal. Pack it up and go home. We're all tired of hearing this drivel.
http://www.independent.co.uk/news/science/boys-like-blue-gir...