Personalized 18th Wedding Anniversary Happily Married 18 Years Ago Youth T-Shirt. Celebrate your anniversary in style with our 18th Wedding Anniversary Happily Married 18 Years Ago apparel and gifts. Show your love and commitment to each other with these beautiful and unique items. 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.