Excuse the absolutely horrible quality of these two videos I took them around 30 minutes after doing a water change when the tank lights were off so all that I had was the lights in the room on so please excuse the horrible glare.
It appears what I am assuming is a female has begun to change to her spawning dress and has caught the attention of the largest N. Nematopus in the tank. The two swim around together and are doing their little dance as can be seen at the end of the second video, they also are spending a fair bit of time behind that large rock in the Center of the tank. She seems to have caught the attention of more than one male though