Flatline/Pharma/Tarn Sparkmate au loosely based on the fic Empire of Dirt by interface on Ao3
Pharma and Tarn are Sparkmates, and they found out at Delphi. Tarn immediately shut down the bond, making sure the blackmail was "impersonal." Since Pharma is an autobot and the autobots are the enemy, having a sprakmate does not matter if that sparkmate is an autobot.
Tarn used to hook up with other mechs but stopped after discovering the bond despite having no intention to pursue it. Something pretentious about the sanctity of a sparkbond. Hypocritical purple prose as per usual.
Since the civil war ended earlier in favor of defense against the Quintisons, Pharma's greatest crime was letting a few patients slip away instead of directly killing them. While the Decepticons do not care about this, it is still something that weighs heavily on Pharmas spark. Having his talent recognized by the Decepticons Pharma is placed as one of the lead doctors for the Decepticon Air Force.
This eventually leads to Pharma meeting Flatline post-victory while working in the new hospital. Flatline, who was not forged with a sparkmate, relentlessly pursues Pharma despite the jet trying to drive him away, "You know I have a sparkmate, right?"
Eventually, Flatline breaks through Pharma's icy walls, leading to a tender moment where Pharma reveals: "My Sparkmate wasn't who I desperately wanted them to be. And when I finally did meet him? It was a brute who wanted nothing to do with me and everything to do with what I could give him."
To which Flatline responds with,
"All I want is to give you everything I have"
After this, an official relationship between the two finally starts. However, Tarn still lurks...
With the war over and the turbulent beginnings of reconstruction having ended, Tarn has found himself with free time despite his position as head of enforcement. Coming to terms that the Autobots, or well the former Autobots, has been an adjustment for Tarn. But time and a direct order from Lord Megatron have certainly helped.
Now that he is "allowed" too, Tarn decides to look into Pharma. This is done with the intent of wooing his one and only sparkmate, only to discover the "great betrayal".
In reaction to this news, Tarn conveniently injures himself in a fit of rage; Thus he is needing to go to the hospital. After refusing treatment from any other doctor, Tarn is able to ambush poor Pharma. Unfortunately, Pharma was unable to check the name of the belligerent patient demanding his treatment.
Pharma refuses to leave Flatline. And since Flatline is the Decepticon CMO (or whatever), Tarn can not make him "dissappear." This leaves Tarn in a predicament; if he wants to woo Pharma, he will need to get through Flatline, and it seems like the only way he can do that is to woo Flatline as well.