Meaning either "Suck My Hoe" or "Slap My Hoe" used when on person is angry at another and wants to fight so the person says SMH, and the angry person must slap his hoe (a.ka. bitch) or if someones in a sexual mood and is hitting on on person if that person says SMH, the sexual person must then suck his hoe.
Person 1: Come over here and fight me bitch!
Person 2: Well you can just SMH!
Person 1: *Slaps hoe or,
Person 1: Hey what up baby?!
Person 2: wtf do you want?
Person 1: I wanna fuck.
Person 2: *Sighs, smh
Person 1: *Sucks hoe