Judas didn't dare to refuse the sop and must of
heard the whispering. He must have known
what Jesus meant. Jesus already knew his
actions and now it was too late.

Judas got up; his heart had to have been full of
rage, greed, anguish and shame, that he had been
discovered. And he must have felt he had to get
out of there before the disciples understood what
Jesus had said.

But before he could go Jesus spoke to him that
they all heard, "That thou doest, do quickly."