A child who wears sweat pants at every opportunity. This child is usually socially inept and has a love for military vehicles, trains, model airplanes,pokemon(or other card game) and lego. They come in pairs and only ever interact with their pair, or other sweatpants kids. One of the pair is usually a borderline sweatpants kid. The other is usually an extreme sweatpants kid. If the sweatpants kid has no pair, he is referred to as a sweatpants single. They usually have bad hygiene and do not shower on a regular basis. In medical terms, it is referred to as SKS, or Sweatpants Kid Syndrome. To be diagnosed with SKS, all symptoms need to be present. The cure for SKS is maturity.
Cool guy - how the fuck does he know so much about trains?
Cool guy 2 - hes a fucking sweatpants kid
Cool guy - o that would explain why it smells like shit