Knowledge of local rules and customs will not only help you stay out of trouble when travelling, but also open the door to a unique and rewarding travel experience.
As an example In many Muslim countries, particular those in the Arabian Gulf, public displays of affection, including holding hands, cuddling and kissing can be punishable by law.
http://www.thehindu.com/todays-paper/tp-features/tp-metroplus/etiquette-matters/article641292.ece