Question: We discussed whether Robert loved his brother Renly or not. […] I never envisioned their relationship as more than lukewarm. (Jaime said Robert hardly could stomach his brothers (plural form)). Which is correct?
GRRM: “There are many different kinds of love. Robert was dutiful toward his brothers, and no doubt loved them in a way… but he didn’t necessarily like them. His relations with Stannis were always prickly. Renly was the baby of the family, and spent little time in Robert’s company until he was old enough to come to court. I suspect Robert was fond of the boy, but not especially close to him. Stannis always resented being given Dragonstone while Renly got Storm’s End, and took that as a slight… but it’s not necessarily true that Robert meant it that way. The Targaryen heir apparent had always been titled Prince of Dragonstone. By making Stannis the Lord of Dragonstone, Robert affirmed his brother’s status as heir (which he was, until Joff’s birth a few years later). Robert could just as lawfully retained both castles for his sons, and made Joffrey the Prince of Dragonstone and Tommen the Lord of Storm’s End. Giving them to his brothers instead was another instance of his great, but rather careless, generosity.”
( source via nobodysuspectsthebutterfly)