My children have taken my sudden outburst (BP and BPD tendencies)...it is very humbling to apologize to them...a sincere apology does do wonders...

Sounds like grandpa may need some ground rules...a good candid over the phone conversation can set up scenerios that will help him take "time outs". What ever the problems in the past write them down and help him find away...ultimate rule...if he can't follow them or becomes disruptive you will need to ask him to leave...this should be done before he arrives if at all possible, so he can decide if he can live with these conditions...If not possible...as soon as all the initial flurry is over with have the conversation then...