The next morning, David asks for a temporary leave of absence from work and then attends one final case with Mr. Spenlow. The case is "amusing," and David is feeling optimistic about his chosen profession as he heads to Steerforth's home. Littimer is not there (to David's relief), but Mrs. Steerforth and Rosa Dartle are, and are glad to see David. He is a little disconcerted, however, when he notices that Rosa keeps glancing back and forth between him and Steerforth. What's more, she seems to follow them around over the course of the day. Finally, when all four go out for a walk, she grabs David's arm to hold him back for a moment.
Rosa evidently suspects Steerforth of having an affair—or, at least, of having fallen in love—and consequently spends the day jealously watching for hints that she's right.
Rosa asks if David's work is really so interesting that it prevents him from visiting the Steerforths' more often. David agrees with her suggestion that it can be "a little dry," and Rosa says it is natural for him to want a break from it. She then begins to drop hints about Steerforth, however, implying that he is unlikely to find David's work interesting, but that he must be "engrossed" in it, since he has been visiting his family home so rarely. David finally catches on to her meaning and says that Steerforth has not been spending his time with him. At this, Rosa looks pale and "sharp" and begins pressing David to tell her what Steerforth and Littimer are up to. David says that he doesn't think Steerforth is up to anything, but Rosa's expression only grows more pained, and she swears David to secrecy.
Although Rosa is often an unlikeable character, her frustration is understandable. Despite knowing perfectly well what Steerforth is like—she hints here, for instance, that he's flighty and easily bored—she's desperately in love with him, as evidenced by her pained expression when David confirms her suspicions. There's very little she can do about her feelings, however, both because they're unrequited and because she's a woman and (to some extent) a dependent in the household. In fact, she's not even free to talk openly about her feelings, so in some ways she's forced to adopt the indirect way of speaking she uses here, and which Mrs. Steerforth later objects to.
David notices that Steerforth and Mrs. Steerforth seem especially close to one another during this visit. He is also struck by how much they resemble one another in temperament, and thinks that any argument between them would probably be difficult to bridge.
In retrospect, it seems clear that Steerforth feels guilty about his plan to seduce and run away with little Em'ly, and is paying particular attention to his mother in an attempt to make up for it. It's true, however, that Steerforth and his mother are very close and very similar, and the unhealthy intensity of the relationship does lead to an equally intense falling-out, as David predicts here.
David reaches this conclusion after a conversation Rosa starts at dinner one night. She begins by hinting that there is something she wants to know more about, and Mrs. Steerforth tells her to be more direct. The two women then get into a discussion of whether Rosa's "mysteriousness" is her "natural manner," with Rosa feigning surprise at everything Mrs. Steerforth says and finally saying she will "learn frankness" from Steerforth. Returning to the original topic, Rosa then asks whether people with similar personalities are more likely to argue seriously. Steerforth believes this is true, so Rosa brings up him and his mother as an example of what she means. Mrs. Steerforth says that she and Steerforth "know their duty to each other" too well to quarrel, and Rosa says she is very relieved.
Rosa's remark about "learning frankness" from Steerforth is, first and foremost, a jab at Steerforth for concealing his affair with Emily. In a broader sense, however, it's also a jab at the hypocrisy of Steerforth (and perhaps the upper classes in general). "Frankness"—that is, naturalness—is almost by definition something innate rather than learned, so the idea that Rosa can become frank by modeling herself on Steerforth would be nonsensical except for the fact that Steerforth's apparent honesty is itself a performance. Although Rosa is not above snobbishness herself, her comments here do undermine the idea that there's anything inherently noble about the upper classes.
Meanwhile, David has also noticed that Steerforth seems unusually determined to make himself agreeable to Rosa. Rosa initially resists his efforts to win her over, but softens by the time dinner is over and everyone is sitting around the fire. Eventually, Rosa begins to play the harp, which Steerforth tells David she has not done in several years. Steerforth then sits next to Rosa and persuades her to sing an Irish song, which sounds almost "unearthly" to David. The mood is broken, however, when Steerforth puts an arm around Rosa and jokes that they will "love each other very much" going forward; Rosa jumps up and strikes him before running from the room.
Just as he did with his mother, Steerforth attempts to ease his guilt over his coming affair with Emily by being unusually kind to Rosa. This suggests that he's aware on some level that Rosa is in love with him, but the brotherly joke he makes toward the end of the scene also implies that he's in denial about just how deep her feelings run. The scene also underscores Rosa's previous jab about Steerforth's earnestness, since it's actually Rosa who bares her feelings in the song she sings, and Steerforth who laughs them off to avoid dealing with them.
Mrs. Steerforth enters as Rosa leaves and asks what the matter is. Steerforth replies that she is compensating for her previous good mood, and his mother warns him not to provoke her. Later, as David and Steerforth prepare for bed, Steerforth once again asks David what he thinks of Rosa, and David wonders what it was that upset her earlier. Carelessly, Steerforth says it could have been anything.
Although Steerforth is clearly joking about Rosa's need to "compensate," it's a joke that again allows him to ignore her feelings for him, and the role he has played in encouraging them: he attributes her bad mood to her natural temperament rather than his own words. Steerforth is not only unable to control to his actions, but also unable (or unwilling) to take responsibility for them after the fact.
David tries to go to his own room, but Steerforth stops him and asks him to always "think of him at his best, if circumstances should ever part them." David reassures him that he always thinks the best of Steerforth, and they say goodnight. Before leaving the next morning, however, David peeks into Steerforth's room and sees him sleeping as "easily" as he had at Salem House. Back in the present, David hints both that Steerforth's peacefulness is surprising in retrospect, and that this was the last time he ever saw his friend. For a moment, however, he says that he wants to remember Steerforth in this way.
Steerforth's request once again implies that he knows in advance what he is going to do (namely, run away with Emily), but doesn't feel he can stop it. It's fitting, then, that David is reminded of him as a boy, since Steerforth hasn't truly grown out of his youthful irresponsibility; the fact that he's sleeping "easily" suggests that however much Steerforth may regret the effects of his upcoming actions, he doesn't truly view himself as to blame for them.