Personalized Stays At My Birthday Party Youth T-Shirt. Funny birthday Youth T-Shirt - White with Las Vegas parody, party hat and balloons, says WHAT HAPPENS AT MY BIRTHDAY PARTY STAYS AT MY BIRTHDAY PARTY! 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.