During my brother's wedding, my mother managed to keep from crying until she glanced at my grandparents. 

My grandmother had reached over to my grandfather's wheelchair and gently touched his hand.

That was all it took to start my mother's tears flowing. 

After the wedding, Mom went over to my grandmother and told her how that tender gesture triggered her outburst.

"Well, I'm sorry to ruin your moment," Grandmother replied,

"but I was just checking to see if he was still alive."