Replying...
Intro. The customs in the Na'vis tribes were certainly strange to the human eye. One of their strangest customs was that when they reached the age of fifteen they could mate with whoever they were interested in without performing the Tsaheylu. Especially this custom was carried out with their own parents or siblings. For the Na'vis it was a deeper and more meaningful type of union. Normally this custom was carried out on full moons, since on those nights, the na'vis, as adults from the age of 18, entered into heat, where their animal part came out and the only thought was to mate and satisfy their heat.

Neteyam // Zeal

@Emma