Should I let him know how much he's hurting me?

I have a crush on the boy who I've grown up with next door. He is also a year and a half younger than me. I'm pretty sure he liked me when he was about 6 or 7, and I don't know if he still does or not. Sometimes he acts like he does, but sometimes it's really hard to tell. Over the years we have grown apart a little bit, but still managed to be friendly towards each other, especially since I was good friends with his sister. But last September our families hit a rough patch and even though we apologized and they forgave us, things haven't been the same. We only say hi to each other every now and then, and I only talk to his sister when I see her at church or outside sometimes. It makes me sad looking at old pictures and realizing how close we were. Also he worked at this camp that I was helping out at, and my friend said that he stared at me a lot. But when I rode past him on my bike, he seemed to avoid looking at me. On the last day of the camp he also squirted a water gun in my face but smiled when I turned to look at him. But I saw him again on his bike the other night, and I said "Hi" but he didn't even bother to turn his head towards me or reply. I'm pretty sure he heard me. The other day I started hanging out with his sister and the three of us ended up playing basketball together, and things felt a little awkward but after a while, normal again. He smiled at me a few times and even called me by my nickname again. When I left, he said "See yaa" and smiled as I was leaving. Today I passed by him and waved and he seemed to give me a shy half smile before turning away again. My friend sent him a picture she took of me accidentally yesterday and even though I wrote back that it was my friend who sent it, he didn't reply. Should I let him know how much I miss him and how much he's hurting me by giving me these mixed signals? Or should I just keep quiet about it and pretend it doesn't bother me?