R&B singer Teairra Mari has found herself a “Sponsor” in rapper Soulja Boy Tell ‘Em, as he stars as the leading guy in her new music video (which would also star Gucci Mane if he wasn’t sitting in jail right now). “Sponsor” is the debut single from Teairra’s sophomore album At That Point, due in stores sometime in Spring 2010 (after being pushed back nearly a year). Check out the new video after the cut…