If you feel like acting a bit more outgoing than you normally do, go for it! You have a good enough head on your shoulders to know what is and what isn’t appropriate, so have fun. Holding back from saying what you really feel might seem like the polite thing to do, but in reality it’s somewhat dishonest. You have the ability to put things in a very tactful way, so say what you mean. You have every right to your feelings, and you have every right to express them.