Ugh! This is how my son ended up on his own. I locked him out and took his key. He stayed home sick that day and was then going out that night. I said no way. If you are sick from work, you don't go out that night. But he said he was going anyway.
My husband stood around and never said a word. I couldn't believe I was making my son move out and his father says nothing. Grrrrr.
I cried for 2 days. Lost my appetite. He thanks me for making him go out on his own. Sometimes!
I can't believe I made it through 4x.
Your boys sound like good kids. And you are very involved parents.