Phew-that was close

I know it's coming...

1. Yesterday, I overheard kid #1 saying to kid #2: "See? These are the male whales and these are the female whales. Males are like girls, and females mean boys."
(uhm... yeah!!????!!!??Ha!!)
2. Then today at breakfast, "Boys and girls? How do you know the difference? I mean, how do you know if someone is a girl or a boy?"

Are you curious how we answered???...My hubby said "That's easy, buddy. Just looking at them is quite clear. Us boys have a lot more energy than girls, right?"
Which Kid #1 agreed with whole heartedly.
For me, I looked out the window and said "Oh my goodness! Do you guys see that? It's raining outside!"
And the conversation quickly changed.
Phew, that was a close one.
I need to do some major praying on how to bring this up...any ideas anyone?
Do you recommend any books that are helpful in explaining it according to the Catholic Faith and the beauty that our God created us in? Boy! I wish there was something like Theology of the Body for 2nd graders!!! (bigtime beginners!!!)
Thanks and God bless,
Mary