Smile or not?

At the western wedding, everyone expects to see the bride feel happy which means she've got to smile and laugh a lot. At the eastern wedding, the situation is just opposite: the bride is expected to feel sad because she is leaving her mother and her own family. With both side's mothers present, what should I do? Smiling much would make my mother sad while being sad makes my mother-in-law uneasy. So I was swinging between thees two expressions, hoping others would not look at me as if I was a clown. :)