He has new hearing aids but still misses much of the conversation. I have explained to him that he cannot get angry with people when he cannot hear them saying Hello. He wants to come to school events and athletic events for my children but makes the group of people sitting around us so uncomfortable with his comments about their rudeness and lack of manners. I have been sitting off to the side away from the group but when a friend comes over to talk he gets mad at the person for not saying Hello and then starts cussing in German. This morning he was very upset with me for talking to him about it. I would like some suggestions.
I know people who have made up business-card size messages that say, "My father has dementia. Thank you for your patience and understanding." They hand them out as needed, and report that everyone has indeed been patient once they understand the situation. If he has dementia that is something that would be helpful for your friends to know.
Whether he has dementia or not, maybe you can head this particular problem off before it occurs. When a friend walks up, say "Nancy, I think you've met my father, Carl. Dad, Nancy is a good friend from church." This is bound to result in an interchange between them, and maybe it will meet Dad's standards. :)
Maybe instead of avoiding the group you could try to sit with them and include Dad in conversations. "Meg, Dad used to run in track himself. Dad, Meg's daughter is the one with a long ponytail -- you'll see her run like the wind and we all cheer." You all came to watch your children and Dad can't be the center of attention. But he can be included, and maybe that would help.
Hang in there, Hart! Although sometimes we think we will die of embarrassment, I don't think it is ever fatal. If your friends know about the situation they will simply respect your kindness to your father in bringing him to events in spite of this difficulty.
Best of luck through these difficulties.
Tell him you agree that some of these people are rude. They should say hello and shake hands and inquire about his health, is he enjoying the weather. etc.
Back in the day these niceties and good manners were expected from the time a child could talk right through old age. I assume you and your dad were raised this way. I was. Unfortunately that is not too often the case anymore. Sometimes it seems no one has any manners left - either in speech or dress.
So try telling him you've thought it over and that he's right - but then tell him that not everyone was fortunate enough to be taught manners as you were.
And remind him that to respond in the way he is responding, with anger and cursing and using a language most others don't understsand - is equally rude. If he expects to be treated with respect, he should lead by example.
If this doesn't work than maybe a quiet moment with these friends would make you more comfortable when this happens? Explain he's getting on in age . . . surely they will understand and do their part?