Suck in Your Tummy

Took a break from the shooting jets of a Waterpark to read my magazine and enjoy some shade. My kids and wife were off on their own wondering and I was happy for the moment of relative solitude. 
Then a group of three stepped in front of me and within earshot. The adult woman was about 30 in my estimate and she was accompanied by two girls. The oldest of the pair could not be older than 10. The mom/aunt/family friend was requesting they pose for a phone and the girls acquiesced in that way kids do when they know