Why was my grandpa so sad that day

I remember that day in 15th may 2015 during my youngest aunt's wedding wheb my aunt was taken to her in law's house my grandpa's eyes were shining with tears and he told he cant see it and went inside. He didnt cry out and show it but he was crying inside then one of my neighbour as put oil on his head and was trying to cool him down. Not only he but almost everyone was crying except the males.