...I'd say it flowed pretty naturally from Devil's Hands and Big Score.
So how many relationships have you been in where it went straight from "There's no chance of a relationship" to suddenly "Omg, we're basically dating now."
That's not what happened at all.
The relationship has been a tug-of-war, with Leela trying to reconcile the fact that Fry's a good guy with the fact that he's dumb and immature. It's a heart-versus-head dilemma, exemplified here by [spoiler]her repeated asking for an explanation for what he's up to and why she should trust him[/spoiler] and ultimately resolved when [spoiler]she realizes she doesn't need an explanation, she knows him well enough that she can trust him implicitly[/spoiler].
So perhaps the question should instead be "How many relationships have you been in where you wondered intellectually if it was a good idea or not but then finally decided to take a chance?"
In which case my answer is "All of them."
re: show continuing
the simpsons.
that is all.
1. I found last night's perfectly watchable.
2. As Constantine points out, it's not an apples-to-apples comparison. Besides the relationship issue, there's the question of continuing creator involvement -- Groening is essentially a rubber stamp on Simpsons at this point, and David S Cohen, who wrote a number of the best episodes, left to go do some other thing. My feeling is that as long as Groening and Cohen have direct involvement with Futurama, we're going to get quality work, though I don't dispute that diminishing returns ARE inevitable at some point.