Visitation after 18 months!

cmanmom

So my exH has been absent for the past 18 months from using his visitation with DS (4 1/2 yrs old).

exH is going to be in town on one of his visitation days and wants to use it.  It's a day, for 6 hours and he wants it all - off the bat, after not seeing/being with DS for 18 months.  This is a standing PP, and I know legally he gets this time but I'm thinking DS is going to FREAK out. Thank goodness he doesn't (and never did) have any overnights, but still 6 hours with a virtual stranger is kind of scary for a 4 yr. old right? 

Can I insist that we have a transition time where I am present for DS sake?  Or at least cut the visit time down to maybe 2 or 4 hours?  Thoughts?  Maybe do an hour together at a park or something and then he takes him for a few hours just them?