A clever approach to this conundrum is to present the alternate pair in a dream or "historical" episode.
For instance, when Leverage tackles the mystery of D.B. Cooper, fans get to see Parker and Spencer together.
What's so fantastic about this is (1) Parker and Hardison--the official couple--are a fantastic pairing. I doubt many fans wanted to see them break up.
And yet...
(2) Riesgraf and Kane, Parker and Spencer, also had good chemistry, and the characters match each other in other ways. In "Long Way Down," Spencer points out their similarities to Parker. It was good that they were the ones to find the dead man in the cavern because they could make the hard choices about what to sacrifice.
(3) Parker and Spencer have an ongoing relationship of teasing and support--Spencer complains about Parker. Parker pushes his buttons.
In truth, they really wouldn't work.
But...
"The D.B. Cooper Job" allows us to see them as a couple without in any way challenging Parker and Hardison's current relationship. It is a clever approach to the problem of pairing up television couples.
Hmmm, if any television show was ever going to sell a polyamarous relationship...
