Personalized Grandpa's Sweetheart Youth T-Shirt. Youth T-Shirt - Kelly Green with lots of hearts and pretty pink text that says GRANDPA'S LITTLE SWEETHEART. Perfect for Valentine's Day. Let the good times roll in a durable T-Shirt that takes kids from school to play in an amazing array of colors. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar.