Bypassing the Office 365 Login to SharePoint Online using FBA via ADFS with SSO

Scenario
The current environment is as follows:

• Office 365 is configured for SSO with ADFS 2.0
• ADFS is running forms based authentication (FBA) using a custom domain (@mydomain.com)
• Office 365 version is E3 Plan
• SharePoint Online TeamSites is implemented and accessible via mydomain.sharepoint.com
• Navigating to mydomain.sharepoint.com prompts the user for Office 365 login. Entering user@mydomain.com provides a link to login at the domain. Clicking the link presents the form to sign-in on the ADFS server

Desired Results
Present a link that will take the user directly to the FBA login and then authenticate them to SharePoint Online. Once logged in, SharePoint Online is presented via mydomain.sharepoint.com. There is no Office 365 login presented.


Solution
If you don't mind having a long URL (which can be easily added to an anchor tag in HTML), here is a solution for the desired results:

1. Logout of Office 365, Windows Live, etc.
2. In a new browser, enter the SharePoint Online address (e.g. mydomain.sharepoint.com)
3. Enter a domain user (e.g. steve@mydomain.com) into the Office 365 login. A link appears to login to the domain.
4. Click on the link.
5. Copy the current URL from the browser and paste it into Notepad (or other text editor)
6. Remove the &username portion in the beginning (e.g. &username=steve%40mydomain.com)
7. The URL at this will work but I did see issues when having other people test it. Therefore, also remove "%252F%255Fforms%252Fdefault%252Easpx" that appears in the URL after the sharepoint%252Ecom (or whatever your .com is).

The resultant URL should be generic now and take users directly to the FBA form to login to SharePoint Online. The user must have a SharePoint Online license assigned in Office 365 as well as have Read access to the main team site.