When it comes to discussing the bosom of even one of the most famous sixteen year old girls on the planet, Madonna's daughter Lourdes Leon (though I think she also goes by Lourdes Maria these days), well, you have to be tactful and just a bit delicate.
Some might consider it inappropriate to discuss a high school aged girl's blossoming, err, thundering large top. And, oh, how I remember my teen years and the true torture of being the biggest chested girl in school. I mean, I wasn't that girl, but I surely never stopped leering at her, especially when I was ensconced in the rafters about the girls locker room.
So, I guess what I'm really trying to say is, no matter how much cleavage young Lourdes displays during her vacation in France, just look away. Or, you know, pretend like you're not looking. Yes! Let us all pretend. And, enjoy.