Host Ira Glass plays tape of two women who ended up as frenemies.They kept trying to be friends, but couldn't help themselves from fighting. Ira then speaks with psychologist Julianne Holt-Lunstad who has run scientific studies to answer the question: why don't we simply end these troubling kinds of friendships? Holt-Lunstad's research also shows that these relationships are much more common than you might think. (7 minutes)

Act One. Chasing Amy.

Family members can easily be frenemies. You're stuck with them. You love them. They sometimes do things that make you feel very strange. Which is how Jeanne Darst felt when her sister married a Muslim man and pulled away from her family. Darst is finishing her first book, Fiction Ruined My Family. (15 minutes)

Song: "My Sister," Julianna Hatfield


Act Two. I Am Here to Make Frenemies.

We head to deep inside the natural habitat of frenemies: reality TV. Rich Juzwiak is a full-time blogger for VH1 and his own pop-culture blog which means he's spent a lot of time watching and dissecting reality TV shows. And last year, he noticed that one sentence seems to repeat an awful lot in the frenemy friendships that happen on reality TV. (5 minutes)

Act Three. Speak Now or Forever Hold Your Peace.

David Rakoff demonstrates—in rhyme—how to make a wedding toast for people you never wanted to see married in the first place. Rakoff is the author of several books, most recently Don't Get Too Comfortable. (10 minutes)

Act Four. The Case of the Long Lost Frenemy.

Ira talks to a woman about a childhood friend of hers who mysteriously shows up after decades, for reasons that are only revealed as their correspondence unfolds. (15 minutes)

Song: "When I Change My Life," Pretenders