A short and funny wedding toast could be something like "May you live each day like your last, and live each night like your first." The strong sexual undertones suggest that the happy couple should consummate their marriage nightly.
It is also appropriate to quote Socrates at a wedding for his famous line: "By all means marry; if you get a good wife, you'll be happy. If you get a bad one, you'll become a philosopher." Additional toasts can include puns on sharing housework, having a short memory when it comes to having a happy marriage, not going to bed angry because the couple stays up to argue and how the secret of a happy marriage really is a secret.