I know it sucks but the reality is when he is with Gabe, Gabe needs to be in charge. Even though your words indicate that is a stretch for him....jump in now, and you will be the go-to person every time there is any kind of 'situation' with Marc at Gabe's place.
Using your house as a punishment is wrong either way. First, b/c your son doesn't see it as a punishment. Second, b/c you would never want him to START thinking that coming home to you = punishment....
