CBS

In this week's episode of How I Met Your Mother, "Twin Beds," the audience is reminded of the fact that Robin has been in serious relationships with two of her four closest friends. In the real world, sharing an apartment with an ex-boyfriend while maintaining a healthy friendship with both him and another ex-boyfriend, who happens to be a mutual best friend, is very simply a horrible idea. But somehow Robin, Ted, and Barney made it work. Their friendship was stronger than any lingering ills from past romantic encounters.

All of this changes when Robin's new boyfriend Don discovers that she has this history with her friends. On its own, this is a reasonable reservation. What boyfriend wouldn't be a little suspicious of the arrangement? Don's jealousy, however, provokes some very uncharacteristic plot turns: Barney and Ted proclaim sudden, violent, passionate nostalgia for their respective relationships with Robin, and Robin abruptly decides that in order to focus on her relationship with Don, she has to take time away from her friends.

There are only three episodes to go in Season 5, so Robin's leave won't last too long, but if history serves correctly, these next few episodes will be pretty sentimental. Hopefully the writers will be kind and toss in a funny montage or two, which are the most consistently strong parts of How I Met Your Mother. This week's montage shows us why Don assumed Ted was gay. Enjoy: