The Irony of Clarissa's Chastity
Clarissa remains pure to the best of her abilities, but Lovelace takes her virginity from her against her will. After all the trouble she's gone to protecting her chastity, Clarissa is devastated. It's like he's taken her reason for living because she allows herself to waste away and die afterwards. She tried so hard to be pure, but it wasn't something she could ultimately control. In the light of that realization, she gives up hope and dies.
The Irony of the Sisters
Arabella is the older of the two Harlowe girls. She is ready to be married and interested in her suitors, but Clarissa is not. Coincidentally Lovelace chooses Clarissa over her sister once they meet. He isn't concerned with helping her family preserve their social prestige by marrying the eldest.
The Irony of Rape
Lovelace becomes so frustrated with Clarissa's constant refusal that he finally schemes to rape her. After he does he discovers that he's only made the promise worse. He was hoping to convince her that she's his property and to finally give herself up to him, but the action has the opposite effect. Clarissa leaves him and cuts off all communication with him afterward, disgusted and hurt by his brutish crime. While Lovelace hoped to own her by raping her, he ended up ensuring she will never belong to him.
The Irony of Lovelace's Refusal to Marry
Lovelace really just wants to use Clarissa with no intention of making a longterm commitment to him. She begs him to marry her, but he refuses. After he becomes obsessively consumed with the desire to own her, he rapes her, and she leaves immediately. Desperate to make her stay, he proposes, but it's too late. If he had agreed before then he would've gotten the one thing he wanted from her.
The Irony of Reputation
The Harlowes value their family reputation above all else it seems. They are concerned with become wealthy influencers, so much so that they place enormous pressure on their children to behave acceptably. Actually their devotion to reputation leads them to drive Clarissa away and marry her siblings off to dishonest people. They lose their fortune and fame in one fell swoop because they tried to hold onto them so hard.
