Hi, T. -
You have received lots of great advice, which confirm the thoughts I wanted to share with you from my own experience.
(1) This phase too, shall pass. A teenager is successful just making it through the teenaged years with hormones exploding and emotions intensified. Time for us Moms to "lighten up" and keep communication lines open.
(2) Your son has a male image by being with your brother, but who made that decision?
One of your readers suggested that he may be missing most of the school activities by splitting his time between the two homes and forgoing weekend activities where he attends.
(3) Another reader said that your son may feel a bit lost now that he is living away from his family. (Of course, at his vulnerable age it would probably intensify in his mind and he would never, never admit that fact.)
(4) Without knowing your circumstances at all, my suggestion is to approach your son and say how much you miss having him a part of your home all the time, and would he consider moving back to attend the school nearby for the remainder of his high school years. Then to look at his expression, his voice tone, his body, and his words to come closest to knowing exactly how he feels about it.
(5) Vocalize to him all the positive things about him that you can think of. Don't look for a positive response back. As one of your readers suggested, he'll be "back to normal" when about 25 years old!
(6) Keep saying affirmative things to and about your girl, too...she is also going through the teenage syndrome. You & I made it through...remember? It wasn't so long ago.
I pray for you to provide a Christian home for your children.
If you pray for His help, the Lord will answer.
God bless you, T..
M. T