Tsahaylu, reproduction, sex and pleasure

[Human No More]

Interesting discussion on IRC thanks to Eltu. We know that tsahaylu gives two Na'vi a really deep, unparalleled connection to each other, and is also a pleasurable experience. We also know Na'vi reproduce similarly to humans, although it is most likely that sex in itself would be pleasurable too.

The question is, would the Na'vi have sex simply for pleasure or not? This could be if they aren't mated with anyone, or even if they were. Obviously, there's the chance of pregnancy, but they could always use some form of contraception, or another theory was that there could be a biological element that only make reproduction possible with their partner they have made tsahaylu with.
Since the Na'vi lack many of the human taboos (e.g. wearing far less clothes than most humans), I'd doubt they would see sex purely for pleasure as wrong, and they would appreciate that people have basic needs, particularly since it's mentioned in the survival guide that choosing a mate can take years. On the other hand, when they've mated for life with someone, I'd see this as being less likely.