Lucas is a sad faggot who plays runescape while he's having an operation cos he cant bare to be away from runescape for to long nerd. His mum is a slag.
A bundle of sticks is commonly referred to as a faggot. A bundle with very few sticks (less than 3) may be called a sad faggot. Therefor the phrase "As brittle as a sad faggot" emphasizes the weak and brittle nature of an object. Similar to phrases such as "snapped like a twig" .
Momma always told me to eat my veggies and drink my milk otherwise my bones are gonna be as brittle as a sad faggot