Cooper waits to see if Cesare has any intention of letting him in. When it becomes clear that he's just going to let him stand awkwardly on the door, Cooper becomes exasperated. If it was an ordinary building, he'd break the door down, but this is a home, so he has to wait for an invite. This is karma for making Cesare stand outside at his own home.

"Cesare, cut the crap. What's going on?" He pulled out the first name. This is serious business time. "'N don't lie. I'll know." With the exception of pure sociopaths, Cooper had begun to notice a subtle change in people's emotions, a spike that went up when they lied.