L.A.
When he is 18 you can kick him out . Till then, give him a heads up what the expectation is for him to continue to live in your home.
Job, pay rent, pay a portion of the bills. follow the household rules.. whatever you and your husband decide. Have him sign a written agreement.
As long as he follows all of this and you and your husband want to allow him to continue to live with you guys,great.
If he does not follow the rules and you and your husband decide he is no longer to live with you. Change all of the locks on your home. Stop payment on his phone, whatever.. Make it very clear your son needs to call and get permission before he comes over.
We have dear family friend that went through this about 30 yrs ago. She had 2 sons. 1 quit school 1 semester away from graduating high school and the other 1 yr from graduating. These were excellent students, the boys wanted to become "musicians".They told her she was responsible for them till they were 18. They loafed around got into legal trouble. On the 18th bday of the youngest son, she hired a company to go to her house and take all of their stuff and place it on the front lawn. She had the house emptied, changed all of the locks and had a Realtor sell the house. She moved into a 1 bedroom condo. These boys floated around and finally about 4 years later got it together. got their GEDs and both graduated from college. Tough love. They are happily married with children and very Conservative.. It cracks me up the way they act like their mother did with them. I remember them just being 2 losers for so long.
I am sending you strength.