"Like dissolves like" is a nearly universally applicable and well-known rule of chemistry. Nonmixing of polar and non-polar molecules commonly drives the formation of interfaces and is enforced by favorable intermolecular interactions (e.g., electrostatic, dipole and hydrogen bonding) in a polar media, and entropic effects (e.g., the hydrophobic effect in water). In this work, we demonstrate an instance of the opposite: evidence for the spontaneous formation of co-crystals, possibly solid solutions, between two of the most polar opposites imaginable, small hydrocarbons (methane and ethane) and hydrogen cyanide (HCN). We suggest that such materials can be abundant on Saturn's moon Titan where they could help explain the evolution of both chemistry and surface morphology over a range of timescales.