Though this question has a lot of loose points regarding functionality, I will help you to create a simple flow for your project.
As you mentioned there are mainly three things going on:
i) The poke itself.
ii) Whether a private chatroom has been created or not.
iii) What privacy level to set.
According to me, the flow should be like:
Allow users to poke each other.
If both users have poked each other.
Here the user can either just poke back or create a chat room.
- Now if the user decides to create a chatroom and clicks on the button to create a chatroom.
In this way, the user can create a chatroom, maintain privacy and simply poke back the other user, all at the same time.