Ever find yourself confused about certain aspects of sexuality, gender identity, or gender expression? I've certainly embarrassed myself by mixing things up in the past, but this little crash course is a great helper. And even if you're still a bit confused after you've watched it, that's cool — as long as you remember the part that comes at 2:18.
Some may make the (valid) point that gender identity and gender expression don't necessarily fall under the category of "human sexuality," and that's worth keeping in mind. But the fact that we're having this conversation is hugely important. Like, as huge as that blow-up doll's penis is. Not that size matters.