SPOILER WARNING: Major spoilers from tonight's episode of AMC's "Preacher" (and the Vertigo comic series it's adapted from) follow.
In the "Preacher" comics, during what's arguably the darkest time for the main characters, Tulip and Cassidy start a romantic relationship fueled by drugs, codependency, and depression over seemingly losing Jesse. He's not actually dead, but that doesn't stop Cassidy from taking advantage of the situation and dragging Tulip into a downward spiral. On the page, the plot point's as shocking as it is heartbreaking; although it's been revealed that Cassidy's had parasitic, destructive relationships with many women in the past, manipulating (and getting with) his best friend's girl seems like a line even he wouldn't cross.
In tonight's episode "Monster Swamp," however, it seems the writers are planting the seeds for their bummer of a romance much earlier on. When Tulip mistakes Cassidy for a guy she wants to punish at the local brothel where she was raised, she throws him out the window. Any mortal human likely wouldn't survive the several-story fall and a piece of jagged glass sticking out of their jugular, but our favorite Irish vampire's able to stay conscious throughout the car ride to the hospital. Sensing how guilty Tulip feels over the whole ordeal, he asks her to kiss him. She does, and in a visual representation of their eventual relationship, her eyes hint that she's left cold by the gesture. Cassidy, on the other hand, appears to be in love, gazing up at his attacker while heavenly big-band music plays in the background.
All of this is very much in line with "Preacher's" slower story beats. Everything on the show so far is a little more patient, a little more nuanced, and a little more developed than the comic, and laying the groundwork for Cassidy and Tulip's relationship early on will make his betrayal not quite as out of left field as it is on the page. Read more on this and the rest of episode in tonight's recap.