For a long time, I’ve been trying to figure out what makes “Parenthood” so watchable and addictive, even for those of us who are typically network-averse. It’s not as though “Parenthood” doesn’t wear its primetime NBC-ness on its sleeve. All of the sappy melodrama signifiers are there: the musical montages, the manipulative, tear-jerking plot turns, and the neat, happy endings – if not in every episode, in every season.

But watching Julia and Joel’s marriage unravel while Amber’s cold feet turn to blocks of ice, it occurred to me that maybe “Parenthood” has held our interest because it’s not making any promises. My relationship with “Parenthood” reminds me of a high school boyfriend who was just a little out of my league but who genuinely thought I hung the moon and treated me like a princess (at least until football season started back up). I was perfectly satisfied, but never completely comfortable, because I knew there was no guarantee our relationship would last from one week to the next.

The same can be said for the key romantic relationships on “Parenthood”: Any of them could fall apart at any moment. Some already have, and some are on their way. Camille and Zeek have endured infidelity and at least one separation – two if you count Camille’s current Italian sojourn as a break from her marriage. Crosby and Jasmine pretty much always feel one big fight away from breaking up (again). Amber and Ryan probably should have stayed broken up the first time, and if they make it to the altar (very doubtful), there’s no way the marriage will last. The only romantic relationship that feels truly stable is Adam and Kristina’s – but as the show addressed in Season 2, if their marriage succeeds, it will be a statistical anomaly: In one episode, Kristina referred to research findings that 80 percent of parents with children on the autism spectrum divorce. (This statistic has been disputed.)

For four seasons, we were tricked into believing that Julia and Joel’s marriage was rock-solid, but the pressures of adoption and work-family balance have taken a sudden, dramatic toll. And while it’s easy to imagine that Joel and Julia will get through this rough patch, it’s just as easy to see them ending it for good. Which, in some ways, might be good for Julia: She’s never experienced real failure before now. And her winning streak in life has allowed her to be judgmental, inflexible and sometimes unsympathetic. Between her struggles with her adopted son Victor and the strain on her marriage, Julia’s self-satisfied type-A veneer has begun to tarnish, and her character is more likable and more watchable because of it. (Julia might be miserable, but Erika Christensen is probably having the time of her life.)

Of course, there’s always the possibility that “Parenthood” will have a crisis more tragic than a divorce. Vulture’s recap of “The Ring” this week essentially asked NBC to kill off a character – arguing, counter to my interpretation, that "Parenthood" has kept us *too* comfortable all these years. Jen Chaney wants Joel and Julia to have an ugly divorce, yes, but she also thinks it’s time for someone to die.

I also think we need to see a character die on this show. To be clear: I don't want anyone to die on this show, as I love every single person in this sprawling family (yes, I am including Jasmine!), and the notion of a single one of them leaving this Earth is honestly making me cry as I type this. But that’s why, at some point, it probably should happen. Because this is a good drama, and really good dramas rip you to shreds by reflecting real life right back at you. And what happens in real life, I’m sorry as hell to say, is that people you love with every ounce of blood that pumps through your heart die. Marriages do, too. But still, life has to go on somehow, despite the grief, pain and loss of what once was so perfect and right.

That got me thinking, and then it got me worried. Last season, we learned that Zeek has some kind of heart condition I didn’t fully understand that he was keeping from his family. This season, Camille is away in Italy and Zeek is eating Fruit Loops with whipped cream on top. Is he taking his medication? What if he has a heart attack while Camille is away? I hate how easily I can imagine something like that happening.

On the bright side, Jason Ritter is coming back! Just for one episode, apparently, and not until April. Here’s hoping it’s not for Zeek’s funeral.