Personalized Twins Happen Baby Gift Long Sleeve T-Shirt. Boy or girl twins Long Sleeve T-Shirt - Black matching outfit with tiny stars and twins happen quote. Pre-shrunk 100% cotton 6.1 ounce long sleeve t-shirt. Double-needle stitched neckline and sleeves. Quarter turned. Shoulder-to-shoulder taping. Adult: S, M, L, XL, 2XL, 3XL