Thank you, Ray.
You gave me much to think about. We actually did talk about work attire and what is appropriate. He figured casual Fridays meant basketball shorts and t-shirts. I explained it's more like khakis and polos (the things he sees as dressy.) I guess this weekend surprised me as we haven't had battles before mass in a very long time. Even when he wanted to skip the week before so he could sleep at a friend's house..I told him he could sleep over but I would pick him up for mass and made sure he brought clothes with him. He did put in a plea to sleep in, but I consented to going to a later mass in the next town. He didn't balk at all.
He is often the only one in his circle of friends that goes to church. Their parents often comment on what a great kid he is and his friends have told me they wish they could go to church. I always offer to have them join us, so I don't want to give him reason to rebel. I just feel strongly about showing respect and want him to feel the same.
On the plus side, it seems that your decision involved some discussion with your son. It was not a one sided, dictatorial mandate. In the first place, that doesn't sound like your style -- you're not that type of person. So....your son understands the reason for your requests. I'm sure this carries over into other areas of his life as well. You realize that a few minutes of discussion can save hours of aggravation.
Your son is setting an example for the others -- his way of evangelizing even if he wants to sleep in. By adding a little thinking to the process, you were able to mutually reach a satisfactory course of action--attending Mass elsewhere at a later time. You didn't let him off the hook, but helped accomodate his situation at the time.
Oh, the joys of parenthood......