For a moment Crooks did not see him, but on raising his eyes he stiffened and a scowl came on his face. His hand came out from under his shirt. Lennie smiled helplessly in an attempt to make friends. Crooks said sharply, "You got no right to come in my room. This here's my room. Nobody got any right in here but me."
What is ironic about the this reaction from Crooks when Lennie enters his room?