Woman and three Kids

A woman is pregnant with triplets when she gets shot three times in the stomach. She goes to the hospital, the doctor says everything is okay, and she leaves.
So she gives birth and about ten years later, the first kid, a little girl, comes up to her mother with tears in her eyes. She's holding a bullet between her two fingers, and she says, "Mommy I was going potty and this bullet came out of me. What happened?"
The mother explains everything to the little girl, and then the day continues on as normal.
Then, the second child, another little girl, comes up to her mother with tears in her eyes, and she says, "Mommy, I was in the bathroom and then this bullet came out of me. What happened?"
The mother explains everything to the little girl, and then the day continues on as normal.
Then, just as the mother settles down for tea by herself, her son comes running up to her, crying harder than her other two children had been. Frightened, she immediately picks him up and calms him down until he can speak.
First she asks him if he has anything to show her. He shakes his head, and she sighs.
"Mommy...I was playing with myself and I shot the dog."