After Robin flirts with Barney despite having closed the door to the possibility of a relationship, Lily calls her out on the "Lobster situation," or wanting things she cannot have much like the time she ate lobster in spite of being allergic. Robin comes up with the plan to sleep with Barney in order to get him out of her system. Barney doesn't take the bait and shares his realization that he is still searching for what he really wants in life. Robin is shocked when she tries to seduce him one last time only to find him on a date with her co-worker Patrice. Meanwhile, Marshall and Lily confront Ted about his investment in experiencing baby Marvin's firsts as a coping mechanism to replace his other "baby" the GNB tower he built which is now complete.