It concerns me that you would have to find an 'excuse' or sneak out the loading dock. Whats wrong with 'I have other things to do-enjoy your layover-see you at pick up!'. If that causes a problem then there are many greater problems that need addressing first!
There's been a generational change. No longer any "requirement" to meet for drinks at 6. Prospective recruits feel free to know your time off duty in a slip port is yours to do as you wish.