Dean and Jo

Dean Winchester and Jo Harvelle shared a romantic friendship as well as a working relationship. They flirted with each other almost from the moment they met, although they never began a romantic relationship. Jo later sacrificed herself to save Dean's life.

Background
Other than the fact that their fathers worked together, Jo and Dean never really met until Everybody Loves a Clown.

Season 2
They first meet when Sam and Dean come by the diner. Jo points a gun at Dean's back, and he manages to get it out her hands. She responds by smacking him in the face. Once things are sorted out, Dean is about to hit on Jo, but stops himself. This surprises Jo and she tells him that every hunter comes through here thinking they can get into her pants, but he's different.

Whenever Dean visits the roadhouse, he and Jo talk. There was one moment where Jo asks Dean if he is afraid of her mother, and Dean answers yes. Which is why he hasn't tried anything. There is one moment after Jo puts a song on and Dean comments why would you put that on? He later sings it in the Impala.

Then to his surprise, she joins him on a hunt in No Exit. The case was originally Jo's, but her mother won't let her hunt. Dean, though, is impressed with the research and work done with the file. So when she appears, she pretends that Dean is her boyfriend, and he plays along. Back in the room, he is about to send her back when Ellen calls. Jo makes Dean lie for her, and in return he keeps a close eye on her. He is surprised though that she knows she is the ghost's type (which is on purpose). Jo gets grabbed by the ghost, Dean feel guilty for letting Jo down and letting happen on his watch. They eventually find her and with her help they trap the ghost. Their relationship does hit a road bump when Ellen reveals to Jo how her father died. After that, Jo doesn't want much with Dean.

They don't see each other again until Born Under A Bad Sign. Dean comes to her rescue when "Sam" has tied her up, and Dean slashes water on the demon, causing it to run. Jo is surprised that Dean knew. Later, she goes looking for Dean who hasn't reappeared for a bit. So she continues to call Dean's cell and then hears his ring tone nearby and finds him wounded on the boat lauch. She patches Dean up from the gunshot wound from "Sam". As Dean leaves, Jo wants to come along, but Dean refuses to bring her along. He tells her he will call, but she knows he won't.

Season 5
"Hmm. So, dangerous mission tomorrow. Guess it's time to eat, drink and, you know, make merry." "Are you giving me the 'Last Night on Earth' speech?" "What?" "What?" "No. No, but if I was, would that work?"

- Dean and Jo Dean and Jo see each other again after a few years in Good God, Y'all when a town seems to be overrun with demons. They meet up when Dean and Ellen go to rescue Sam and convince Jo and Rufus what's really happening. The two have a pleasant exchange of words with each other and finish the job.

Then Jo comes to help Sam and Dean on a major job. She helps them get into Crowley's so they can get the colt. After, they all meet up at Bobby's where they have a party before they set off. Dean decides to use this moment to make a move on Jo. To Dean's luck, she turns him down, which makes Dean embarrassed.

The day of the mission comes and they head out. They spilt up to cover ground, and when they return they discover Castiel missing. Then Meg arrives and lets Hellhounds loose on them. As they run for their lives, Dean is caught and Jo comes back to help him. Unfortunely, the hellhound goes after her and rips her side open. Dean quickly picks her up and carries her into the general store.

Dean realizes how serious Jo's injury is, and knows she doesn't have much of a chance. Though he does attempt to make a plan to try to get Jo out and get her some help. Jo stops him and informs them she can't move. She makes a plan to blow up to room and kill the hellhounds. Much as it pains Dean, he sees the logic in this plan and agrees. Once everything is ready, Dean says his final goodbye to Jo, and kisses her forehead and then kisses her on the lips. As they leave, he watches the store blow up in horror.

Season 7
In Defending Your Life, Dean and Jo are reunited when Dean is on trial, but she returns as a ghost. Osiris begins to ask her about how she felt about Dean and implied that she cared for for him than a friend. Jo insisted that they were former working partners. As the trial goes on, Dean feels guilty about doing her first case, and how it eventually led to her death. Jo tries to assure Dean its alright but is cut off by Osiris.

When Dean is declared guilty, Jo is sent after him, and when she finds him she doesn't attack outright. After talking, she sets up the room in a similar fashion of her death. Dean doesn't stop her as she prepares this, and as she is how to blow the room up, Jo disappears.

Note

 * Jo was meant to be a love interest for Dean, but it turned out to be a brother-sister relationship.