Gregor Blanco leaped in front of David Peralta to get a high-five and left his teammate crestfallen

There are rules we have to maintain a polite society. You bring enough candy to share with the entire class, say "Oh, I'm busy that night," when someone asks you to go see a terrible movie with them and you never, ever cut someone in a high-five line. 
Grégor Blanco broke that most sacred of duties during the D-backs' game against the Giants on Saturday night. 
After AJ Pollock homered in the first inning, Blanco and David Peralta were waiting to celebrate with him. But Blanco couldn't wait. He had to celebrate that very instant. 
Unfortunately, just like when you answer someone saying hello, but they're talking to the person directly behind you, Peralta became the awkward bystander:

"It's kind of funny how these guys respond to one another after those special moments," D-backs manager Torey Lovullo told MLB.com's Steve Gilbert after the game. "Peralta is always the first one on the top step and every once in a while Gregor gets a little playful and he jumps up and steals a little thunder and wants to congratulate the player first. I get a kick out of David's response and his facial expression."