My question involves criminal law for the state of: Illinois.

I have become aware of a relationship between a 19 year old girl and a 15 year old boy. Both are open to friends about the fact they are dating, including posting pictures of themselves cuddling after a kiss on Myspace. I know the 19 year old to be sexually promiscuous, but there is no evidence, that I am aware of, that they are having sex.

Is there any crime being committed here?