Dierks Bentley is not one to overlook a teachable moment. Just hours after wife Cassidy gave birth to their son Knox, the singer was having lunch with his daughters (ages five and 2), trying to explain the differences between boys and girls and why some boys undergo a circumcision soon after birth.

With a semi-graphic tweet and a photo, Bentley tells his story so much better than we can:

"I try not to post too many pics of my kids, but this is too good: me trying to explain what circumcision is and why," the singer wrote later, including the above photo of his girls.

Little Evie seems to be taking the news as one would expect a 5-year-old to. Jordan -- who turns three on Christmas -- looks almost as if she's saying, "Thanks for ruining my appetite, Dad!"

Baby Knox Bentley was born Wednesday night (Oct. 9). Previously, Tropical Nights: Boots in the Sand headliner Bentley talked about how he was nervous to have a son who might that turn out like he did. It sounds like the country singer was a bit of a hell-raiser as a kid ... Who knew?