Alright, as we all know, Leela was abandoned as a baby by her two parents Morris and Munda. Of course, they did this so that their daughter would have a better life above the surface than in the sewers.

But of course, life at the orphanarium growing up believing to be a one-eyed alien does not equal popularity.

As she grew up, she felt conditioned into believing that she was worthless and bullied by other kids. Even when she took karate, she was put down because she was a "girl". When she left the orphanarium, she had to build many walls to hide her pain during her first job by having a overconfident personality, but her inner child was very much hurt.

It wasn't until when Fry, on December 31st, 2999, got unfrozen and met her. One chase throughout New New York later, this scene...

As the series progessed, we see Leela having many boyfriends that either match her or earned her sympathy.

But of course, all those guys ended up to be revealed as frauds or just used her for her gain. Now that hurt her inner child more.

In between those guys, Fry would always try to earn Leela's love which she often rejects. From being on the moon with her to spending the rest of the day with her while having those parasites. From staying by her side while she was in the coma to making an entire opera about her.

Of course in midst of it all, Fry would always respect her decisions because he sees through all the walls she built; he sees the little Leela inside her so hurt and abu$3d by many. He sees the Leela that wants a hug, to know she is loved, and more importantly, to know that she can be silly and vulnerable around.

So even when Leela said no to his dates, he still (surprisingly) finds a way to help her heal. Even finding her parents...

As Fry became more mature emotionally during the fox era and after all the Futurama movies, she finally said it.

During the Comedy Central Era, the two find themselves in a on-off relationship (Yes, it is annoying. So I can agree with the people that hated the Comedy Central era on that), but as I can tell that (and this is my opinion so don't come after me haters!) it is clear that Leela wasn't yet used to Fry's childishness and his willingness to be with her.

Even when he shows that he finds her beautiful with one eye, as seen in "The Prisoner of Benda," she immediately showed hostileness towards this. But of course, at the end of the day (while they have the swapped bodies) she realized Fry's undying desire to be with her.

Throughout the rest of the Comedy Central and the first 2 Hulu seasons, the pair seem to have a steady relationship. But it was the events of 50 Shades of Green that kind of cemented their love.

While the plot seem to be boring and have nonsensical things in them (as said on Capt-t-Leela [may her account rest in peace and be remembered] post she made with @ladybender in that), the episode of course ends well with the mirror showing that Fry and Leela are indeed soulmates.

Okay, this took longer, but yay, you made it to the end! I know I left out a lot, but this took me an hour or less. But I hope you enjoyed this!