The guards didn't stop even though Duke Yuletide made that outburst.
They just followed the fourth prince's orders and brought the duke's wife and daughter up onto the stage.
When they saw everyone that was there, the two of them started trembling in fear.
The only one that they could turn to was Duke Yuletide since he was the only one that was on their side. Both of them immediately looked at Duke Yuletide with looks as if they were begging him for help.
Duke Yuletide had a look like he wanted to rip the fourth prince to pieces after seeing the way that his wife and his daughter looked at him.
However, the guards were restraining him and wouldn't let him move at all. So it wasn't as if he could do a single thing physically.
The only thing that he could do was say, "What do you want?"