Why might Peewee be disrespectful to the Vietnamese women?

Peewee may be disrespectful to Vietnamese women because he does not trust them.
The text gives us some strong evidence for why Peewee is suspicious of Vietnamese women. In the beginning of the story, Richie Perry (the narrator) bunks with Harold "Peewee" Gates when he gets assigned to the Twenty-Second Replacement Company.
Immediately, Richie realizes that Peewee is suspicious of Vietnamese women. The latter maintains that one of the Vietnamese ladies cleaning the barracks is a Vietcong in disguise. Richie does not believe Peewee, of course. For his part, Peewee sets out to prove that he is right. He calls loudly to the cleaning lady and addresses her as "Mama Cong."
The cleaning lady just shrugs, which prompts Peewee to repeat his address to her. Immediately, the Vietnamese woman turns around and leaves. Peewee is exultant that she does so, as he thinks that it proves his point about Vietcong women in disguise.
Later in the story, members of the AVRN (Army of the Republic of Vietnam) detain a Vietnamese woman and her two children. The South Vietnamese soldiers bring the trio to military headquarters. Since the AVRN interpreter at headquarters cannot get any important information from the woman, the troops decide to let her and her children go.
As for Peewee, he decides to make the Vietnamese children a doll from grass. He sets to work and cannot wait to present his gift to the children. Meanwhile, the Vietnamese woman hands one of her children to an American soldier from Charlie Company. Almost immediately, the child explodes in the soldier's arms, killing both of them. When the soldiers finally realize that the mother had rigged up one of her children with a bomb, they shoot and kill the woman and her second child.
Richie relates that Peewee then threw his grass doll on the muddy ground. In the aftermath of the deaths, Peewee refuses to discuss his feelings. However, this episode clearly shows why Peewee may be disrespectful to Vietnamese women: he does not trust them.