Wayne is so sympathetic that there are moments of “Terms of Endearment” when it’s Mulder who comes off looking like a jerk.
“Terms of Endearment” is a monster-of-the-week episode divorced from the show’s larger UFO mythology, but its story is still impacted by Mulder and Scully’s search for “the truth.”
It’s set during a time when the pair have been thrown off the X-Files and replaced with the Smoking Man’s son, Agent Spender. Their replacement puts the case in the shredder when he gets it, but Mulder finds it by picking through his garbage.
So for most of “Terms of Endearment,” Mulder is without the moderating presence of Scully in Roanoke, and he does the kinds of things his partner might normally be able to stop him from doing.
Namely, he harasses Wayne. As Laura is being arrested, Mulder—already convinced that Wayne is a devil—turns to Wayne as he leaves his house, saying, “I know what you are.”
Later Mulder teases Wayne as he trails him in his car, forcing the devil in disguise to do some quick thinking to not reveal his second secret family to the agent.