How can I private with multiple guys?

Yes. Select "Groups" from the top left of the chat, at the bottom, choose the pink “+”

Enter a name for the room (Be sure to select "Password Protect")

Enter a password (Recommended: an easy to remember one!)
OR enable “Approve Users Manually”

Enable video/audio options if you would like those features enabled in the room/group.

Share the room name and password with the guy(s) you want to join you in this private room.