Somerhalder's rep has declined HuffPost's request for comment.
The pair, who became an item shortly after Reed's divorce from Paul McDonald and Somerhalder's split from longtime girlfriend Nina Dobrev, were friends before sparking up a romantic relationship. The 26-year-old actress and McDonald called it quits last spring, after almost three years of marriage. Their divorce was finalized earlier this month.
Somerhalder recently shared a photo of his reported fiancee on Instagram, calling her "incredible":