A cat suddenly rubbing its head against someone and purring is a sign of happiness, which means it likes you very much. Or maybe it wants to leave its scent on you, marking you as belonging to it. When a cat is very clingy, it is possible for a cat to treat its owner as a lover.

Of course, if a cat is hungry, it will be more clingy to its owner and then rub its head against its owner. Any part of the body, and the abdomen is still purring, the cat needs to be fed or given water in time.