Six Pack

So, I am currently the co-leader for Achievement Day girls at my church. There are about 10 girls aged 8-11 in our group and they are... energetic. Tonight, we had them bring a family picture and a project they are working on or some other show-and-tell item so they can get to know each other better. I brought one of the paintings I've been working on them. I told them that I like to paint, that a lot of the members of my family like to paint and that my little brother's job is to be an artist. Here's the conversation from there:

Abby, age 8: You're little brother is an artist?
Me: Yep.
Shannon, age 9: What's his name?
Me: His name is Jeremy.
Jada, age 8: Is he cute?
Me: Of course he is! He's my little brother!
Jada, age 8: Does he have a six-pack?
Me: {laugh}
Shannon, age 9: A six-pack??
Jada, age 8: Yah, a six pack!
Shannon, age 9: A six-pack of what?
Jada, age 8: No! Like on his chest.
Sara, age 11: They're muscles on his stomach. But only boys have them.
Me: Well, girls have the muscles; they're usually just under a layer of....