I think "stealing an ipad from a 4 year old" is more like it.
Well, it doesn't have to be that complicated. At that age, there is no "sexual desire" or "male-female relations." It's just a simple "who likes who." You could just tell your kids, "some people like girls, and some people like boys, and some people like girls AND boys, and it doesn't matter who you like." There's no need to bring in the whole sex thing until later. Introducing the concept of gays and lesbians to your kid wouldn't corrupt them.