Feeling his oats

Tonight after my oldest attending the "child care" portion of my zumba class, he exclaimed that it really "sucked ass". Yup, you read that right and I heard it right.  Excuse me? and he repeated it!!!  Yeah, this has been happening a lot lately.  Just things here and there that he says or does, almost as if he is testing me or forgetting that he is not 18! I am all for having a good relationship with my son, but not at the cost of his morals and dignity.  I hope and pray he isn't trying this on other grownups!  Not sure what goes on at his father's house (another joy of divorce) but he is old enough to know the differences in how our households are run and swearing is not an option for an 11 year old.  yes, you read that right. 11 going on 25! 

HELP!!!