Thank you very much Maria )

he doesnt need to or he mustn't ? Because as you know its not the same in English

I'm wondering about it too. It depends on the context I guess.

Yoa are very welcome David :)
He does not need to pretend = ему не нужно притворятся
He must not pretend = он не должен притворяться

The Russian phrase is more likely to imply a strong advice.

thank you very much for explaining )