Well, this is a tricky question. While we do have plans to add the ability to add another collaborator/host to your account in the future, for now, there is an easy way to do it (but we can't promise we won't change it!).
1. Click "Start session"
2. Copy that link and share it with your colleague who wants to be a 2nd host
3. Both of you will have the same control panel to facilitate the session