Outlook.com Shared Calendar not visible in Android Calendar App

[AC Question]

My wife and I both have accounts on Outlook.com and for each account we share the calendar with the other person. This has enabled us to see each others Calendars on all devices (PC with Outlook Client, iPhone in native Calendar etc..) The problem is that I can only see my own and wife's calendar in the Outlook.com application on my Android phone, I cannot see her calendar in the native Calendar application on my HTC One M8, that said I can see my own Outlook.com account in the native calendar.