I gotta ask, why exactly aren't Fry and Leela together yet? It's pretty obvious that Fry has been trying to get together with her since the first season, and the only resistance has come from Leela.
Then she was subjected to a mysterious marriage to Fry during a time-skip, meeting a version of herself from a parallel universe who's happily married to Fry after deciding to go on a date with him, and falling for him while his system was infected with worms. When the TV series ended with Leela falling for Fry as a concert holophonist, I thought Bender's Big Score would establish them as a couple. But nothing had happened. Then Leela fell in love with Lars, who turned out to be Fry. Were they finally a couple during Beast with a Billion Backs? Nope. The most we saw was Leela feeling a little jealous when Fry was dating Colleen. Then Bender's Game comes around, and neither Fry nor Leela are showing any interest.
In a way, it's worse than typical "will they/won't they" cliches found in other TV shows. They're put together, only for it to be ignored the next time we see them.