Why did he block me?

Few years ago two friends of mine died within a few weeks apart and I reconnect with a friend of the my family for a long time. Anyways we started talking and I said to him he was hot and he said right back "your pretty hot yourself" then out of nowhere he blocked me from facebook, instagram and other ****. He said he does that to everyone weird I know. I asked a friend of our to ask him but he won't tell him. I did facebook with him once it twice and he seem ok with me then. Why block me?