The meme is crudely depicting a phospholipid, one of the molecules that's part of cell membranes. Phospholipids can be said to have two parts: the hydrophilic "head" and the hydrophobic "tail".

The head is the big round top half of the compound. The term "hydrophilic" comes from the Greek root words for water and love, and typically means that the head is in contact with bodily fluids and cells' cytoplasm.

The tail is the two long bits at the bottom half of the compound. The term "hydrophobic" comes from the Greek root words for water and fear, and typically means that the tail avoids contact with bodily fluids and cytoplasm.

The head is trying to use the tail's explicit hydrophobia as evidence to argue that the tail is secretly "hydrophilic", or "water-loving", but they're using the term in a way that means that the tail secrectly loves water carnally.

Sauce