After Pinkie Pie yelled at Spike for the answers she wanted about her best friends not liking her anymore, Spike gets traumatized and cries in Twilight's home.
Once there was a caterpillar and he was very hungry. Twilight investigates a noise coming from the kitchen. It's a caterpillar and it's very, very hungry.
Spike had his heart crushed thanks to somepony's lies, now he tries to go after another mare. However, this mare has a friend that has taken an extreme interest in the drake.
Spike was once a complete puzzle. All of his pieces fit together perfectly and he fit into life's puzzle perfectly. Then, he lost something, or more specifically somepony. One does not stay the same after losing a special piece of them.