No clue

Awkwardly smile and look around

dance and yell foods in between lines of the song
happy birth day to you
PINEAPPLE
happy birth day to you
CUPCAKE
happy birthday dear Esteban Julio Ricardo Montoya de la Rosa Ramírez
SPAGHETTI
happy birthday to you
PIZZA

I cried out of embarrassment once. I was 13 and my dad and his wife took me out. They had the waiters sing Happy Birthday and everyone in the resturaunt was looking.

I bow and feel proud. Like today!

screech like pterodactyl so you're not the only one that's feeling awkward

Look around the room at every one doing a slow look around while smiling once than stare at cake next look at each individual with a kind of a thanks forcoming look on your face than stare at candles on cake like you are excited to make a wish and blow out the candles.

Stare at the cake and candles and wait with a blank face

Do not sing along, because it doesn't make sense of you to say "Happy birthday to you", Instead, you must, without saying anything, appreciate everyone who are singing.