In the Netflix show Mindhunter, there is an arc about how Ford gets jealous of a classmate of Debbie's, his girlfriend. Afterward, during a sociology experiment involving a black room, he "catches" them together, just sitting kinda intimately. Now, I felt like this was a loose thread and was pretty confused when later in the show they were shown together without resolving this issue.
On the other hand, some people on the Mindhunter subreddit seem pretty convinced that she did cheat on him. Is there some way to establish canon? Something I missed?