How I Met Your Mother

Marshall and Lily end up in a very heated argument after Marshall finds out that Lily is looking into a summer program that could interrupt their wedding plans.
After Robin shoots Ted down for his supposed last attempt at her, of a string quartet and roses, he comes up with one last plan.
Much to Ted's dismay, Robin is planning a weekend trip with her coworker, Sandy Rivers. Ted feels the need to intervene and try to win Robin's heart one last time, so he enlists Barney's help to track down Penelope, an old flame who studies Native American culture, who teaches Ted how to perform a rain dance.
After what appears to be many hours, the skies open up and the rain washes away the camping trip. Ted races over to Robin's apartment to give things one last shot. This time, Ted is successful.
Upon Ted's joyous return to the apartment the next morning, Ted discovers Marshall sitting on the steps outside of their apartment with Lily's engagement ring in his hand, with it being very apparent that Marshall and Lily have either broken up or delayed wedding.