One of the most bizarre of Balinese traditions takes place on the day after the seclusion day, at Banjar Sesetan Kaja, Denpasar.  It is aptly named, Omed-omedan, coming from the Balinese words omed-omed, meaning pulling as it is believed to represent the push and pull of positive and negative elements. It is believed that if the ceremony doesn’t go ahead, disaster will happen. The participants of this ceremony are all unmarried adults aged between 17-30, all members of the Banjar Kaja. A non-member of Banjar Kaja is not allowed to join the ceremony.  

Both loud and chaotic, Omed-omedan follows Nyepi, the Balinese day of silence, which this year falls on March 13. The participants, wearing t-shirts and sarongs, pray in the temple inside the Bale Banjar. A short while after they line up and go out into the street following the direction of older members of the Banjar.

As the Beleganjur troop start playing their traditional instruments, the sacred kissing ritual begins. The girls and the boys line up facing each other and following a signal from the Hindu leader, they rush to meet in the middle; the boys pulling the girls towards them in a frenzied embrace.  Meanwhile, other members of the village hurl buckets of cold water over the willing participants.  Most of the time a boy will only succeed in snatching a kiss on the cheek but the brave ones manage to steal a kiss from the lips. 

sumber :

http://www.nowbali.co.id/publications/item/170-omed-omedan-balinese-mass-kissing-ritual.html