Why does Prince Prospero seal himself and his guests in the abbey in "The Masque of the Red Death"?

Prince Prospero sealed himself and his guests in the abbey
for more than just one reason, when you really read about
it.

The obvious reason is, of course, escaping the Red
death. This disease was supposedly ravaging the town and Prince Prospero had the
opportunity (due to his rank and position) to localize the disease and move away from
it.

The second reason, however, is because he wants to
flaunt precisely the fact that he thinks that he is in control, and he invites his
courtiers sort of to re-establish his invincible position, entertain them, and show them
how much money can actually buy.

Third, he wants to use
this escape as an excuse for non-stop irresponsible behavior. While the Red death
loomed, people had to be careful not to become sick. Now that the courtiers were away,
they felt safe enough to want to tempt fate. They were feasting, and celebrating being
better than everyone else.

Yet, when the Red death showed
up IN the abbey and surprises everyone, the real weakness of human reality exposes
itself.