That Guy Season 1 Episode 21 Water Tower

While painting a weed leaf on a water tower, Kelso falls off after trying to fix the poorly drawn leaf. Since Eric's mom is a nurse they take Kelso to Eric's house. Eric walks into his parents bedroom to see them having sex. Being so disgusted by what he sees he is nearly incapable of doing anything, which includes sleeping. After while his parents come to the accurate conclusion that Eric is on drugs. Though they are right, the clues that led them to the answer are not why he is acting.