When Pip is first invited to dinner, Mr. Jaggers asks Pip who one young man is that is called "the Spider" and Pip tells him he is Bentley Drummle. Jaggers observes, "I like the look of that fellow."
At dinner Pip meets Molly, the housekeeper, whose strong wrists Mr. Jaggers is proud to display. Then, toasting the young men, Mr. Jaggers, who draws out the worst in people, says, "Mr. Drummle, I drink to you." Pip remarks that Mr. Jaggers follows Drummle with interest, noting the "boorish sneer of the young man."
Later, in Chapter 48 of Great Expectations, Pip again speaks with Mr. Jaggers who announces to him that Our friend the Spider,...has played his cards. He has won the pool.” This means that Drummle is going to wed Estella. Of course, using verbal irony, Jaggers does not consider Drummle as any friend of his, nor of Pip, who is clearly a rival. Jaggers goes on to say that it will be a struggle of the strongest between Drummle and Estella, suggesting that the Spider, who, he implies, has caught Estella in his web, may dominate if he beats Estella. This certainly is a case of dramatic irony since Drummle does later do just that.