One or several girls are allowed to hide their faces under the family 'joker' mask and to play the legend of marital duty which, according to Om Bahadur Rai from Shankhuwa-Shava in eastern Nepal, is as follows:

In the old days of satya yuga, there lived a man who had married his three young sons to three young girls of the village. But trade obliged the three bridegrooms and their father to travel abroad for many years. The wives languished at home. When they returned from their long journey, the husbands had grown old. In order to check their wives' fidelity they knocked at their own doors with masks on their faces, dancing, singing and playing the madal (small drum). They offered them gifts and asked for shelter. The wives did not recognize their husbands, but did not forget their duty and refused to give them shelter. Later on the youngest one recognized her husband's voice. They all hugged each other and could finally perform their duty! Since then Rai people have been carving masks for women to wear at weddings.

http://www.mikalina.com/Texts/masks_of_himalayas.htm