Bum Cracks?

We had a friend come over for a play date the other day. This little girl has been over many times, but today she turned to Emily and said, "Emily I see your butt crack! haha-ha!" I was shock that this little girl said this, but then Emily turned to her and said, "I don't have a crack!"

I then told the girls everyone has a bum crack. Emily then said, "But where's my bum crack? I can't see it!" 

"It's there, it's small but it's there." I told her. Emily said to her friend, "Don't look at my bum crack!" 

Never thought I would ever say the words, bum crack to my kids. There's a first for everything I guess!