Just tell your family, very firmly, what you would like to do, or not do, on your special days. Make sure that they understand that you will not co-operate with any other plans.
I was 80 last July, and myself, son, daughter and two GC just went out for a meal. They produced a small birthday cake for dessert.
In November the whole family assembled in Australia for my younger daughter’s wedding. A few days after the wedding they threw a belated birthday celebration for me. A barbecue, naturally! I don’t usually like parties, but this was a nice relaxed event around, and in, the swimming pool. It was lovely to have the U.K. and Aussie branches of the family all together there, with the other people that I know.
My 81st, on the 29th, will be a much quieter affair. Hopefully we will, once again, go out for a meal.