Vicky I agree there should be more involvement with son. Then the OW will not use her son to bring H around her. it will remove the middle man. If H wants to return - strict NC but H will need to co-parent but you will have to be open in being part of that.
Me 53 H 50 D16, D29 M 22 years bomb 7/08 INH - alien pod replaces H 8/08 - OW (direct report), I work there also bomb II - H moves 10/1 expose ow 10/22 D to be final 9-09