The tree was an ancient from East Orient and he was more divine version of Josh.
He spoke in different language to them, it was probably mandarin or Japanese, and in his language, it meant that he was impressed by this erotic scenario and now this eastern wanted to fuck Zara, and in a way he was Josh as they were connected to the tree of their soul.
"Well, i've been standing here and watching the impressive erotica between two lovers and i believe that you are me. ahhahaha" said the tree in english as he looked at Josh. Both Zara and him sprung behind and Josh held Zara in his arms.
"Who are you and what did you want and why do you talk speak and look like a human that just transformed from a tree." Zara asked, as both of them stared at his engored penis because he was more larger than them.