His DUI and punishment (or lack of) has had no effect on him, in his mind he has gotten away with the "crime" and unfortunately, this only adds fuel to his fire,IMHO, he will most likely get another one very soon.
In the meantime, just be clear, no, I need some quality time...for me.
Living with an addict is always confusing and unpredictable, take some time for you, go to Florida and enjoy the time with your son, you both deserve a break!