My son is 11 1/2. He has had "girlfriends" ever since he was in kindergarten. Fortunately for me, his best "girlfriend" lives in about 30 miles away from here. They have been friends since first grade, because they have attended the summer science camp sponsored by my husband's employer since then. Several times a year, we make a special arrangement for a meeting with this girl and her family, usually at the Children's Museum at Christmas, or at the fall "Headless Horseman" event at Conner Prairie (we live near Indianapolis).
I have to say that some of the girls at his school are very aggressive in a skanky sort of way, and as a future MIL, I am very open in my observations of this type of behavior. He attends a Catholic school, and I feel very strongly about modesty in behavior and dress. There are some girls that I would not feel comfortable at all about his "going out with". But, like the rest of us, he needs to make his own choices and decision. I will give input, but, ultimately, the choice is his.