#jack willis

As a relevant aside, early seasons David Duchovny and Gillian Anderson didn't consider their characters to be very sexual (post here.) M/S was partnership first, intense emotional underpinnings second. Repression can only run so deep or last so long if there is an equally intense mutual attraction. (I believe @deathsbestgirl touched on this theory before; and I'm coming around to it slowly-- at least per the actors' intent.) Be that as it may, it would be wildly out of Mulder's character not only because of the nature of their connection (established as early as the Pilot's basement) but also because that is not how Mulder operates, even selfishly.

Further canon backs up these points.

Firstly, Mulder's parents were emotionally manipulative (alternating between distance and tears to get him to leave well alone); yet, the only time Mulder pressed Teena was after the death of his father (and nearing the death of his partner.) He could have squeezed his mother's heart by begging, perhaps broken down her walls in desperation... but chose not to.

Secondly, Mulder's intimate relationships were also emotionally manipulative and reestablished through the same means. However, even when he suspected each woman's disloyalty (or treachery), Mulder held his tongue and investigated. In fact, he never confronted nor duplicitously retaliated with either-- just grimly accepted their choices.

My last point: even if Mulder had tried to toy with Scully's emotions, would his methods have worked?

Canon is against this, as well. She often pushed back against Mulder's theories, particularly in areas more vulnerable to deception (be they her beliefs, her abduction, or her cancer.) Not to mention her dating history-- leaving Daniel Waterston after learning about his wife (post here); or parting with Jack Willis on cordial terms; or engaging with Ed Jerse only after his honest declarations; or spotting but letting Eddie Van Blundht's oddities slide; or returning to Daniel before leaving him again, no matter his wishes.

More to the point, she has sensed motive from Mulder before. While he's a clever secret keeper, Scully's always detected his emotional disturbances. If he'd tried to utilize her trust for his own aims, she'd have dressed him down and left.