Birth Control
Sister Mary Ignatius is pleased with Gary for not using birth control, which is against the beliefs of the Catholic Church. Ironically, he has done so because he is gay and sleeps with men, which angers her instantly.
Confession
Gary tells Sister Mary that he went to confession that morning to confess his sins of sleeping with a man. Ironically, the Sister kills him after this admission, saying that she did it so she'd know he'd go to Heaven with no sins on his soul.
Aloysius
Aloysius confesses to Sister Mary that he's an alcoholic, beats his wife, and thinks about suicide. Ironically, she tells the rest of the group that at least he turned out well, unlike the rest of them.
Diane
Diane has come today in order to kill Sister Mary for making her the way she is. Ironically, Sister Mary was carrying a pistol and Diane is killed instead.
Adult
Aloysius is a grown man who has come back to perform a play for Sister Mary and leave. Ironically, she won't allow him to go, even to the bathroom, just as she treated him as a child.