Son, it's time you learned about sphingomyelin. Sphingomyelin is an important lipid found in the membrane of most eukaryotic cells. It has two hydrophobic tails and a hydrophilic head group, making it an amphipathic molecule. Associations between cholesterol and sphingomyelin are highly favored due to the saturated nature of sphingomyelin's acyl chain and its ability to hydrogen bond to stabilize the interaction. Together, these molecules can form liquid-ordered phases within the cell membrane.