I'm scared of my Neightbours

Last week, the neighbors that have lived next to me since I moved into my house moved out, after several months of having their home on the market. After they left, the house sat empty for a few days, and finally, the new neighbors moved in. They seemed average enough; a white couple in their mid to late 30’s, with a daughter that must be about 6 or 7. While they were in the process of emptying the truck that contained all their belongings, I stopped over at their new home to introduce myself before heading to the store.
Paul and Mary seemed very kind, and their daughter Andrea was as pleasant as could be. We had a back and forth that consisted of basic introductions, cliche pleasantries, and the like. In hindsight though, something struck me as odd. Paul looked past me at my house, and commented on it. “I really like your place, I very much admire the way you do things.”. I thanked him, we said our goodbyes, and I went on my way. In my rearview, I noticed the three of them waving to me until I was down the street, and out of view, which was admittedly kind of weird.
I didn’t see them again until I was doing some yard work yesterday. Here’s where things kind of took a strange turn. I went to my shed and got out my cordless hedge trimmer for my front yard bushes. About 3 minutes later, Paul was in his front yard trimming his bushes as well. Not a big deal, surely just a coincidence. Paul and Mary’s house is bigger than mine, with a noticeably bigger front lawn, therefore they have more bushes in front of their house. I got finished trimming mine, but Paul stopped when I did. He just left a few feet of bushes untouched and put his trimmer away the same time as me. I was kind of weirded out at this point, so I went inside. As did Paul. This was the first truly odd thing I noticed.
I spent the night at my girlfriends last night. I told her what happened and she encouraged me to just shrug it off. I went to work thist morning and had a normal day, nothing striking me as weird until I left. About a block after I’d turned out of my job’s parking lot, a car pulled up behind me. It followed me all the way home, and it turns out it was Paul. I was a little unsettled by this, but again chalked it up to random coincidence. But after I got out of my car, I got my mail. So did Paul. I went in my house, Paul went into his.
This was beginning to thoroughly creep me out. Then, night came. My bedroom window faces what I assume to be the bedroom that Paul and Mary use. This is because I saw Paul through the window. I walked past mine, and a second later, Paul walked past his in the same direction. I walked back, so did Paul. I decided to test it. I walked back and forth three times, then stopped with my back to the window, and hopped once. Paul did the exact same thing I did each and every time, on about a one second delay. As Paul turned around from his hop, he looked me directly in my eyes and smiled a normal, toothy smile. And waved. The same wave he and his family had done when I left the day I met them.