The following quote from the opening chapter of the novella concerns Lennie always getting into trouble.
"You can't keep a job and you lose me ever' job I get. Jus' keep me shovin' all over the country all the time. An' that ain't the worst. You get in trouble,. You do bad things and I got to get you oul." His voice rose nearly to a shout. "You crazy son-of-a-bitch. You keep me in hot water all the time." He took on the elaborate manner of little girls when they are mimicking one another. "Jus' wanted to feel that girl's dress--jus' wanted to pet it like it was a mouse-- Well, how the hell did she know you jus' wanted to feel her dress? She jerks back and you hold on like it was a mouse. She yells and we got to hide in a irrigation ditch all day with guys lookin' for us, and we got to sneak out in the dark and get outta the country. All the time somethin' like that--all the time. I wisht I could put you in a cage with about a million mice an' let you have fun."
George and Lennie are now camped beside the river south of Salinas. Their latest trouble occurred in the little town of Weed, which is situated in the far north of California. They have had to travel a great distance to get to their next place of employment, first having stopped in San Francisco to visit an employment agency that evidently handles itiinerant farm workers. George has been furious at Lennie ever since they escaped the mob in Weed, and this appears to be his first opportunity to release his pent-up anger and frustration.
George does not specify what sorts of trouble Lennie has been creating for both of them or what the "bad things" have been. He tells about Lennie grabbing the girl's dress and then says, "All the time somethin' like that--all the time." Does this mean that Lennie has been doing similar things with other girls? George doesn't really know exactly what started the trouble in Weed. He was some distance away when he heard this girl screaming. Then he and Lennie had to start running, and they have been on the run ever since. So George has had no information about the incident except for what he got from Lennie--and Lennie lies to George consistently, as he does about the dead mouse in his pocket in this opening chapter.
Since Lennie likes to stroke little animals--mice, rabbits, puppies--it would seem likely that he would be attracted to little girls rather than grown women. The fact that George "took on the elaborate manner of little girls when they are mimicking each other" is a clue that he is talking about a little girl in Weed. If that was the case, why didn't Steinbeck have George say so? Probably because that was not a subject that was mentionable in literature in the 1930s. Lennie told George he just wanted to feel the soft material in a girl's dress, but the girl took it to be a sexual assault, and that might have been pretty much what it would have developed into.
Curley's wife is not far from being a little girl herself. According to what she tells Lennie about herself in the barn, she was planning to leave home with a traveling actor but her mother wouldn't let her go because she was only fifteen. She had been frequenting a dance hall in Salinas at that age and apparently she married Curley right after being prevented from going off with the actor.