Unlike a Sugar Daddy, a Sugar Brother is typically a younger average looking male who spends inordinate amounts of money on an attractive popular female. They typically receive their wealth from a third party (rich father or mother), but flaunt it as if they made the money themselves. Sugar Brothers typically hang out with other "regular guys", but feel they have a higher status due to the female they bring to social occasions. Sugar Brothers will give a lot to the female ( money, rides, drinks etc...), but they will receive absolutely nothing in return from the attractive female, other than her presence.
Brandon: Hey man that Thomas guy is an absolute pimp, look at that chick he is with.
Josh: No man, he is a Sugar Brother.
Brandon: Oh, so he doesn't get any on the side, huh?
Josh: No, he spent $100 dollars on her and she didn't even say thank you.
Brandon: Oh, is that why he say he looks at her as a sister.
Josh: Yeah, most likely he tried to go out with her, but got denied. Now he is a Sugar Brother.