Lennie can't take his eyes off of Curley's wife, and she doesn't make it easy to put his eyes anywhere else, either.
Slim, the "prince of the ranch" (about whom you will hear more later), walks by and sends Curley's wife on her way.
Time for another lecture for Lennie's benefit: stay away from this woman.
Lennie, with an admirable sense of self-preservation, says that he doesn't like this place—but they've got to stay until they can buy a ranch of their own.
Slim now stands in the doorway.
You get the sense that Steinbeck has a little bit of a man-crush on Slim: he's practical, tough as nails, understanding, highly skilled at his job, cool and calm, and still humble. Heck, we have a bit of a crush on him.
In comes another visitor: Carlson, who asks Slim about his new litter of puppies.
Maybe Slim could give one of these puppies to Candy as a replacement for his ancient dog, which stinks so bad it deserves to be shot. (According to Carlson.)
At the mention of the word "puppy," Lennie starts wriggling with pleasure. Pure petting pleasure.
If Lennie had a Tumblr, it would totally look like this.
Curley shows up at the door (don't these people do any work?) looking for—you guessed it—his wife.
He and George snark at each other a little, but no one whips out any roundhouse punches. Not yet, at least.