Kristin Cavallari, 37, debuts relationship with model Mark Estes, 24
Kristin Cavallari has a new — much younger — man in her life. The “Laguna Beach” alum, 37, debuted her romance with 24-year-old model Mark Estes in a Tuesday Instagram post. “He makes me happy,” she captioned a photo of the pair posing for a selfie in Los Cabos, Mexico. Estes, for his part, later …