Chocolate contains chemical called phenyl ethylamine or phenylaline that is produced in our brains when we falling in love, and that gives the same emotional high related to amphetamines. Many psychologist feel that chocolate is an instant "love booster" and an automatic sweet taste in our mouths. And with some people, both chocolate and love can be addictive. Anyway, the idea of giving chocolate to someone we care about is a way to stir up the same emotions in them as well. As with all drugs, the phenyl ethylamine will wear off if it's not produced due to real emotions. Some also say that "sweets for my sweet" is a pun for giving any candy to someone you care about.
 

Taste of love

When people are in love they just seem to automatically develop this type of dialogue. We often refer to someone we care about as Sweetheart, Sugar Pie, Honey etc. Researchers have found that when we fall in love, a chemical called phenyl ethylamine or phenylalanine is produced. This drug is responsible for that erratic, psychotic love high that we all feel. When phenyl ethylamine or phenylalanine is flowing through our veins it's as if we are on amphetamines. We can stay up all night and work all day the next day. And a pheromone called androstenol is also released, which heightens our sexual attractions. Thus, we also end up producing what is called a sweet taste in our mouths and we start spouting off phrases like "luscious" and "sweet" and "honey" and other things that we like such as "muffin" or "cupcake" or "pudding." However, there is nothing as bad as love gone wrong! And so then we suddenly start spouting off words that have to do with being disgusted, depressed, angry, bitter etc. These are like, "a sour taste in my mouth" or "foul mood" or even being a little "stinker."