Sopranos: Carmella and Tony, Meadow and Finn

Tony and Carmella slept together, and enjoyed it but Tony left before Carmella woke up to "avoid sending the wrong message" as he told Dr. Malfi, and Carmella got on the phone to her lawyer to get divorce proceedings going in earnest.

Meadow and Finn were having problems too: Finn wanted to go back to his parents in San Diego for the summer. Meadow, afraid he'll bail, becomes demanding and difficult. So Finn proposes--at least he got it right. End of show: Meadow on the phone to Carmella to announce her engagement while Carmella looks out to the pool where Tony is floating like a bloated marine mammal.

Why do people behave this way? Why didn't Tony stay the night? Why doesn't Carmella just put a stop to the whole thing? Why did Meadow make more demands because she was afraid that Finn was cooling towards her? Why is it that when we want someone's favor, dread the loss of their friendship and feel insecure in the relationship, instead of extending ourselves to secure it, we undermine it?

Why aren't we rational self-interested choosers?

Of course one can read it as a Prisoner's Dilemma. Tony, Carmella and Meadow are betting that their partners will defect and playing the D strategy to counter. But it isn't a Prisoner's Dilemma strictly speaking because there are feedback effects: a player's countering a predicted defection makes the defection more likely. The rational play, I think is the leap of faith

Whether it's rational though depends on how heavily you weight avoiding rejection and failure, and that should be a matter of taste about which there is no disputing. But it still seems irrational to weight the avoidance of failure heavily if there are no opportunity costs.