Abaddean
From Super-wiki
Abaddean het fanfiction pairs the characters Dean Winchester and Abaddon in a sexual relationship.
While the ship may have existed in Season 8, Dean's tension-filled encounter with Abaddon in 9.02 Devil May Care caught many viewers off-guard... and intrigued.
Similar to Samifer (Sam/Lucifer), the term "Abaddean" has also been used to refer to Dean being possessed by Abaddon, as she threatened to do in 9.02 Devil May Care.