Black Boomerang UFO tree level sighting West Islip LI. New York 1998

My wife and 2 kids in late summer 1998 just returned to our house in West Islip (south shore Long Island) from a day trip on Fire Island. It was near sunset so it was still light out. We were all enjoying the fresh air on the back porch and I noticed a very large black boomerang shaped UFO pointing and moving north along the treetops that grow along the backwater along the east side of rt 231 up from main st to about the Union Blvd (which is to the north of the house). Several houses in the area. I saw this UFO actually touching and bending the treetops as it moved unaffected and very steadily at about walking speed (3 to 4 mph) northward. When the UFO was parallel to our house it stopped moving. We were kind of excited and I told my wife to quick go get the video recorder. My son doesn't remember this (he was just seven at the time) but he exclaimed, "maybe there are aliens inside!". I was trained as an artist and always had very good vision. I looked carefully for details on the UFO and I could see that it was faceted and the surface looked Velcro like with a little more roughness than actual Velcro. I can also say this UFO was very stealthy looking except that I have seen stealth bombers in flight they moved a lot faster had apparent jet propulsion and made noise. This UFO had no props, jets, nor made any noise at all and had no windows etc. Only 4 feet in depth at the center so this would not be easy for anyone to be in. remained in place not moving at tree top level just beyond out backyard fence for several minutes and then very quickly went straight up as my wife came out with the video recorder. By the time she got it turned on it was at about several thousand feet and she got about 30 seconds of video with the boomerang way up in the sky and a jet flying past it. It flexed one of its wings almost making it look elastic before it continued rising straight up and out of sight into the sky. I don't know where that video is. I gave it to a coworker who was a UFO enthusiast, was very interested, and he had seen many on a regular basis when he was living in AZ. He said they were metallic and ball shaped and constantly jets would chase after them and they would zoom off. But he never figured out what they were. My wife thinks we still have a copy of the video somewhere but I have not come across it (old video cassette). But that is it for this one. I have more incidents I witnessed and will report here as well just for the record. Maybe someone else saw this boomerang? If I ever come across the video I will submit it but it doesn't give you as much info as I just did from my visual. Video only shows a very distant boomerang silhouetted in the sky, one wing flexes a little then a jet goes past then the battery ran out. MUFON CMS# 77654