Do I smile at everyone? Do I sing along? Do I look at the cake?

Thank them and offer them cake ?

Turn to the person on your right and start singing it to them.

Make a meme while they're singing

Wave you finger in the air and pretend to conduct an orchestra

EAT the CAKE!

*heavy breathing* prepare to blow out the candles

sacrifice a body to satan?

Jump on the table and start breakdancing

What do to?