There is a 19 older brother who has just moved back to our city. This son has been a major problems over a number of years and is being a negative influence and things have escalated since his return. I am hurt by the lies my 15 year old is saying about my husband and me and am in shock he wants to leave our abuse-free home where the only real expectation placed on him is accountability of where he is, to go live with his father who he calls names and has not had a good thing to say about over the years. Dumb excuses like this. Making a stepfamily work is a really hard job.
People underrate what's involved.
It sounds as if you and this boy's stepfather have done your very best to support him in living a decent life and have loved each other and him. It sounds as if your son is experiencing his surges of energy in these areas now. However, barring these possibilities, I think you are wise to let him have a chance to live with his biological dad and see what it's like. In this way, your son's relationship with his father is different from your relationship with this exhusband. The more your son can respect him, the better for his own self esteem.