Scott Disick, eat your heart out! Sofia Richie looked like a ray of sunshine on Instagram while rocking a bright yellow string bikini. The model, 21, covered up on the bottom with a pair of jeans in a matching yellow hue as she prepared to hit the beach with a friend. She had a patterned tote slung over her shoulder and cool black sunglasses as she took the mirror selfie with bestie Tess Kemper, whom she called her “twin.”