Before I could say “I’m gay,” I was mouthing the words to "Check On It," by Beyoncé in the mirror, flipping my hoodie like it was 30 inches of honey-blonde bundles, and batting my lashes in secret.

When I began writing Experimenting With Babies–a book of science projects parents can perform on their own kids–my youngest son, Benjamin, was still in my wife's belly, kicking around with the ...