I dont know how that got to be but im a big supporter of the Xfiles and ive like seen almost every episode and not once did it mention Mulder being the father of Scully baby  Cant have watched very carefully can you William being Mulders son is frequently referenced to in the final episode Just off the top of my head  Guard What are you thinking about Mulder My son His mother  Scully Our son Mulder I gave him up Our son I was so afraid you could never forgive me  Not to mention the meaningful looks that Mulder and Scully give each other when the officiator at the hearing asks Agent Scully isnt it true that you and Mulder were lovers and you got pregnant and had his love child