Oh, this was so sad. It makes me curious to know the backstory of the couple. I love how the main character was trying to convince her/himself that she/he loved him, and that jumping was worth it. It was just so realistic. The short sentences kind of disrupted the flow but it wasn't so bad, I could still read it perfectly fine. I like how the story doesn't have an obvious amount of description because it suits the story and is easy to read. I felt like I knew the main character without knowing them at all - if that makes sense.
There was only one mistake I picked up: And with one swift moment, I felt his hand jerk my forward. - 'my' should be either 'mine' or 'me.'
I'm not really a fan of super-short one-shots, and abrupt sentences usually annoy me, but I like this. I like how there's a sense of unknown about it and how you don't explain why they're doing what they're doing, they just do it. Their sudden actions fit with the waterfall's sudden drop and kind of tie everything together. Well done. :)
I liked how you used really short sentences, to emphasise how nervous she was. Although He was looking down into the water, something I dared not to do. The part in bold seemed a bit awkward. Maybe it's just the way I'm reading it :XD
I sort of liked that it didn't have any proper descriptions, it made it seem more blunt and real. (:
There was only one mistake I picked up:
And with one swift moment, I felt his hand jerk my forward. - 'my' should be either 'mine' or 'me.'