We’ve been talking about sex around my house a lot lately. As my 10-year-old gets ready to enter middle school next year, he’s been getting increasingly curious about bodies, puberty, and of course, s-e-x. He’s not interested in having sex, he’s quick to inform me ― in fact, the first time I explained the physical machinations of intercourse, his initial response was, “I don’t know, I’d rather play video games.” But he is interested in understanding sex, a circumstance that has led to a series of increasingly difficult-to-answer queries along the lines of “But what does semen look like?”