The first season of 13 Reasons Why examined the factors that led Hannah (Katherine Langford) to conclude that her life was no longer worth living. But those 13 tapes didn't tell the whole story — nor did they reveal every relationship Hannah had before her death. One of the most shocking moments of season 2? The reveal that Hannah and Zach (Ross Butler) had (lots of) sex – mostly over the summer between sophomore and junior year.
As far as anyone listening to Hannah's tapes could tell, Zach simply had an unrequited crush on Hannah, and any chances he seemingly had with her ended when he stole her compliments from communications class. That was actually one of the "reasons" Hannah listed for taking her life: Zach's careless cruelty.
In reality, Zach and Hannah had a relationship which extended far beyond this slight. Zach actually apologized to Hannah — something she didn't mention on the tapes — and afterwards, they started hanging out. That summer, after some sweet heart-to-hearts and bonding time, Hannah decided that she wanted Zach to be the one she lost her virginity to. The two began a very high school quest to make sex fun, and eventually achieved their goal to an amazing pop soundtrack.
This information comes out at the Bakers' trial against Liberty High School, and not everyone is okay with it. The revelation breaks Clay (Dylan Minnette): he was away at his grandparent's house that summer and lives with the myth that he would have dated Hannah had he stuck around. Maybe that's true, but it's hypocritical and sexist of Clay to judge Hannah for having sex with Zach, as Justin (Brandon Foley) points out.
That's one of the reasons why I loved this moment from season 2. Hannah's satisfying sex with Zach reminds the audience that she was a teen girl, one entitled to explore her sexuality with whomever she chose; she didn't deserve the slut-shaming, bullying, and eventual assault that came with her simply existing in a young woman's body.
The saddest part of the Zach and Hannah saga (super sweet and shippable while it lasted) was that Zach was too much of a coward to stand up to his friends — the ones who routinely slut-shamed Hannah. This ultimately led to the end of their relationship, even though they clearly had more than just lust for one another.
It's unfortunate that Hannah and Zach didn't get a chance at a happy ending, but this plot line served a purpose greater than placating shippers: It showed that sex can be enjoyed as long as it's on your own terms, and that there's nothing shameful about it.