Quite simply, when a character gives another character a cute or endearing nickname because the two are either as close as True Companions, or the namer is interested romantically in the namee. The nickname may not be well-received by the one being named, as they find it insulting or embarrassing, but in the mind of the name-giver it's sweet and/or thoughtful. The formal term for an affectionate nickname is a "hypocorism". In short, it's a pet name. Expect The Nicknamer to dole these out a lot. Sub-Trope of In-Series Nickname. Compare Insult of Endearment. Contrast Terms of Endangerment, where an enemy uses a superficially affectionate nickname in an irritating or disturbing manner. See Significant Name Shift, for instances where the name is suddenly gifted.