Children are like penises. Everyone thinks theirs is awesome, but really they're not that special and lots of people have one.
Children are like penises. Once you have one, it controls your life.
Children are like penises. Most women want (at least) one.
Children are like penises. They grow so fast.
Children are like penises. Everyone likes to compare theirs.
Children are like gremlins - one is bad enough but get a group of them and it's pandemonium.