I don't talk to kids about sexual stuff period. Not my job, and they need to enjoy their innocence while it lasts. Not that I agree with everything this guy says, but the bit at the beginning has truth to it.
Or straight, all of which eventually lead to the concept of sex.
I think young kids should do their natural thing and figure this stuff out on their own without intervention. Let them enjoy their few years of childhood before they need to deal with this stuff.