White triangular-shaped UFO over Worthing, UK

On May 7, 2015, during night, a triangular-shaped UFO with three white lights has been filmed while it flying over city of Worthing (Great Britain). What is it?

Witness statement:

Filmed using a Panasonic W-850 camcorder.

I was indoors at 9:45 pm when I felt the need to get up and go outside. (I don't know why though) - I saw flashing lights in the distance and I thought it was a plane at first, yet I continued to film it.

There was a plane in the area at the time of the sighting and filming. I ignored the plane and concentrated on the strange flashing object.

The UFO appeared head on, then disappeared and reappeared across the sky! I didn't even see it move! it just reappeared. Like it teleported!

This went on for some time, and I caught on camera the UFO morphing into a triangle with white bright stationary lights on the top of the pyramid, and down at the bottom (left and right) these never flashed, but in the middle of the triangle, I saw red, white, blue flashing lights.

The triangle UFO morphed in front of my eyes! Disappearing and reappearing across the night sky.

The UFO just disappeared in the end. Blinked out. I was shocked because earlier that day I was outside looking for UFOs using my Infrared and filters on my camcorder. I was even mentally thinking "Come on , I know you are up there, show yourself"!

One hour later, I filmed (but didn't see) a military helicopter scouting the area. The vibration of the Helicopter was loud. I knew (from studying and filming helicopters for a while now, that it was not a civilian helicopter)

I will note, in the Video you can hear my daughter coughing , she has a slight tic due to Anxiety which causes her to cough or clear her throat. This was not an affect of the UFO in any way.