B-Team Friend - A friend who only shows up when you're the last option. They

A friend who only shows up when you're the last option. They're like the person who eats the last piece of pizza.

'I’m with you because my real friends are busy and I don’t want to be alone.'

'I’m the last option, and I’m here because I don’t have anything else to do.'

'I'm the pizza crust, and I’m here because I’m the only thing left.'