Shimmering object gliding across the sky much faster than any aircraft.I was sitting with my wife on our back porch, looking at stars and planets. I was telling her about a triangle shaped craft I saw about two years ago. I said, "I was looking at a spot between some stars, when--" and at that moment, a shimmering craft appeared as two points of light and seemed to glide across the sky, much faster than any aircraft I know of. I said, "Do you see that?" She did not see it. It very quickly moved toward the northeast, when I said, out loud, "Wait, she doesn't see you, come back." At that point, the craft stopped moving, shimmered again, and was not visible.This is nearly identical to the sighting I had two years ago, except the craft had three points of light then, moved toward the southeast, and did the same stop and vanish when I said "I see you." My wife was inside the house that time. This time she was with me, but she did not see the craft. It was probably only visible for 10 seconds or less.We stopped talking and looked up at the area where the craft had appeared. It felt like about 5-10 minutes passed, and then I asked her why she thought it only appeared to me. She was uncomfortable talking about it outside, so we went inside. At that point we looked at the clock, and we had been outside for about 30 minutes. We both experienced the time as roughly 15 minutes, maybe 20 at most, but 30 minutes had elapsed according to my cell phone and the clock inside. Our dog reacted as if we had been outside for a long time, barking the way he does when we get home after being gone for awhile.