Why are my boyfriends friends all calling me cupcake?

so today i was hanging with my boyfriend and some of his friends and his older brother and they all have nicknames for each other like my boyfriend is spikey because of the way he spikes his hair and our friend jorge is gorge. so they were like we need a nick name for you and his brother goes i know we can call her cupcake. when i asked why cupcake his brother goes because your sweet and tasty. what is that supposed to mean and why am i now getting texts that say hey cupcake from his brother.