Dragon Ball: Why didn't the Monkey King use Dragon Ball to revive Grandpa?

There is this passage in the Dragon Ball, which explains why the Monkey King didn't use the Dragon Ball to revive his grandfather. About 70 episodes. In order to save Upa's father, a group of people went to look for the dragon ball, but the last one was nowhere to be found, so they went to find their mother-in-law. Mother-in-law received100000, and they didn't have that much money, so mother-in-law asked them to hit five people.

The Monkey King went through five hurdles and killed six generals, and finally defeated the last man, and the last man was his grandfather. According to the setting of the animation at that time, you can't be resurrected after being dead for more than one year, but the Monkey King still said that he would resurrect Grandpa, but he refused. The reason why his grandfather refused was that there were many beautiful girls in the underworld, and he was very happy in it.

Not the kui is a big disciple of Master Roshi, even like his own master. Later, the Monkey King met his grandfather again. At that time, his grandfather's official position in the underworld was very small, and according to the animation settings at that time, people could be resurrected indefinitely, and no matter how long he died, he still didn't resurrect his grandfather, perhaps to satisfy his grandfather's wishes. After all, there are so many beautiful women in the underworld.