Lex was taken by surprise as he was honestly not expecting it. Mostly it was because the 'opportunity' he was presenting to Aegis was already actually taking advantage of him to do his own work.
Still, he could understand the gesture. After all, as a crown prince, he was surely taught etiquette and surely put a great deal of emphasis on reciprocation.
"You really did not need to," said Lex, "but since you have already gotten something, I will not refuse your good will."
"Great," Aegis said with a hint of excitement in his voice. "We need to go somewhere to get to it, so whenever you're ready we can head out."
Had it been before, Lex would have hesitated to leave the tavern. He had already exposed himself and if he left the boundary of the tavern he would have been defenceless. But, since he had the Butter knife token, Lex could barely convince himself to head out. After all, in matters such as this, he still trusted the system's integrity.