Well, how do YOU plan on telling the famly in the OPEN about your trip to this place with your H?
Are you goign to LIE and say its a cruise?
If you both ADMIT its a marriage building weekend then your Son can give his F a hug and tell him he's proud of him for keeping the family togthter... that's motivation enough... As long as they say something constructive to motivate him in a healthy direction.