What do you call a situation in which anyone’s gain comes at someone else’s expense

Read the excerpt from act iv, scene iv of romeo and juliet. capulet: good faith! ’tis day: the county will be here with music straight, for so he said he would. [music within.] i hear him near. nurse! wife! what, no! what, nurse, i say! 30 re-enter nurse. go waken juliet, go and trim her up; i’ll go and chat with paris. hie, make haste, make haste; the bridegroom he is come already: make haste, i say. [exeunt.] 35 this scene is an example of dramatic irony used to create suspense since the audience knows that the musicians will not arrive on time. capulet approves of the match to paris. romeo is already married to juliet. the nurse will be unable to rouse juliet.