Irony is a very useful literary tool and Shakespeare uses it widely to convey meaning, to warn his characters or his audience, to create humor and to intensify tragedy. There are three main types of irony and dramatic irony occurs when the audience knows something that the characters do not or one character knows something that another does not, something so crucial that it will change the anticipated outcome in terms of what the unsuspecting characters are expecting. In Romeo and Juliet, Romeo and Juliet have no idea that their fate is sealed and yet the audience know right from the beginning; before the action even starts as The Prologue to Act I says, "A pair of star-cross'd lovers take their life..." (6).
Act II begins after Romeo and Juliet meet and each is overwhelmed by his or her feelings for the other. The dramatic irony begins immediately as Romeo comments on what he has overheard Mercutio say. He suggests that Mercutio has never felt the pain of love, referring to "scars" and "a wound," and Romeo thinks that he, unlike his friend, already knows the pain of love. This is an example of dramatic irony as the audience know that the pain Romeo feels now, knowing that Juliet is a Capulet, is nothing compared to the real pain he will feel when, later, he will pay the ultimate price with his life.
Romeo's reference to the "glove upon that hand" reveals more dramatic irony because Romeo wishes to be so close to Juliet that he is completely reliant on her, such as a glove would be in order to "touch that cheek," (25) and he doesn't realize that his dependence on her will be so complete that he will die after her presumed death. The audience may not yet know how the young lovers will die but the fact that it knows that they will both face the same fate is enough to create the dramatic irony.
There is further dramatic irony in line 70 when Juliet expresses her concern that if Romeo is seen, "they will murder thee" without her knowing that she is as much at risk as he is, as the audience well knows.
I am going to try to help you, but that which you have identified is the big dramatic irony of the scene. Maybe you are to be breaking it down into parts to create more that one irony???
Dramatic irony occurs when we know something a character doesn't know. We know that both Romeo's friends in the beginning think that Romeo is off looking for Rosaline from the preceding scene. Romeo references this by saying "He jests at scars that never felt a wound." So, we know that Romeo is going after Juliet while the boys think he's out with Rosaline. By the end of the scene, we know that Juliet is hiding from her parents and Nurse. The Nurse doesn't know this when she comes looking for Juliet.
Dramatic irony means the audience knows what the actors in the play do not. Since the prologue to Romeo and Juliet informed the audience that Romeo and Juliet are star-crossed lovers, we know it won't end well and can find dramatic irony in Juliet's words to Romeo that she "should kill thee with much cherishing."
Indeed, her love for Romeo (and his for her) will kill him, although she, presumably, speaks metaphorically (and possibly with a sexual double entendre) here.
Juliet also expresses dramatic irony when she says earlier in this scene that she and Romeo are moving too fast: "It is too rash, too unadvised, too sudden." Of course, Juliet can't wait to be with Romeo and talks about how long it will be until they arrange their marriage. An argument could be made, however, that the lovers are moving far too quickly for their own good, shown by their rash suicides days later.