Younger
Lady Bracknell has visited a friend of hers whose husband has recently died. Ironically, she says the woman looks 20 years younger.
Being Ernest
Gwendolen loves Worthing. She says she's always known that she would marry a man named Ernest so it is clear to her that he is the one. Ironically, his real name is Jack.
Proposal
Worthing proposes to Gwendolen and she accepts instantly. Ironically, her mother, Lady Bracknell must approve and therefore though Gwendolen has accepted their engagement is not official until her mother says so.
Truth
Worthing answers honestly to Lady Bracknell that he doesn't know who his parents are. Ironically, she doesn't support his honesty but demands that he produce at least one parent before the season is over or his chance of marrying her daughter will be gone.
Ernest's Death
Jack arrives at his country home to tell everyone that his brother, Ernest has died. Ironically, Ernest (being portrayed by Alge) is inside the home as he says this.