In Black American Culture to sweet has multiple meaning. For example, "Your boy is a little sweet" = Your boy is a little girlish. "That boy is sweet" could mean that he's nice or that he's gay. "He has some sweetness in him" = he's definitely gay / question about if he's ga. Keep in mind that in Black American Culture the term "sweet" isn't negative for gay. It's almost like polite code word for gay, because if you say someone is gay people tend to freak out, but if you say that a guy has some sweetness in him, then for some reason it's not as bad as being gay even though that's what is being implied. In addition some guys can be more feminine without actually being gay, and sweetness would fit that description as well. It would be like saying "Soft like a girl" but not gay. It could be even used as "He's a little sweet but not gay."
I know it's not me because it's even shown here in this commercial.