I can understand how you feel but unless and until you have a written agreement in place I would not take the trip.  Not because he could use it against you but becuase once he is in the home he may move to have exclusiive use and occupancy and for temporary custody of the kids. With a written agreement in place you could agree to have him watch the kids in the home to casue the children less strife (put it in there).  Seek legal help asap.  Good luck.