I take a lot of pictures. My kids are used to it. And I tend to be more discreet about my shooting than not for favoring a candid photo over a posed one.
Generally, this works really well with kids. I sit with them and just shoot, or not shoot. Or tell then I'm shooting when I'm not and vice versa. They've gotten so accustomed to seeing the camera around that they tend to ignore it. And more recently, also me. Calling their name for a quick natural shot is now falling on deaf ears; what I get instead is a face of disarray. They love the attention, but they no longer find it charming to look cute for the camera.
I get a lot of faces these days. I get squints, hands over eyes, wide buggy eyes, tongues sticking out, lips curled, and teeth bared. They don't seem to care.
Someone really should tell my kids that it would benefit them to cooperate in my efforts to make them look their very best - at every age. But then again, what would I have to mortify them with later? When boyfriends come over... and slumber parties need a little entertainment...?
On second thought, I'll let them make their faces. Makes no difference to me, I'm persistent enough to get a good shot.
The silly and future mortifying shots? Just money in the bank.