Thank you so much for the advice. I did go there like you said. I already have him in there. However, I don't see me in there should I be? But he still does not see what I add to the calender. Am I doing something wrong?There's a Google Calendar app in the App Store, provided by Google., Inc., and it has excellent ratings. When you search for Google calendar, you'll find it.
Another option would be to set up his Gmail account on your iPhone and iPad in Settings - Mail, Contacts, Calendars, and enable Calendars only. That way, you get his events, but not his contacts, notes or emails. You wouldn't need a new app either.
I'm a bit confused. What exactly do you expect to find from yourself there?
If you add to the calendar in the built in Calendar app, make sure you've added the event to the right calendar. If necessary, make his calendar your default calendar (in Settings - Mail, Contacts, Calendars - Calendars - Default Calendar). That way, you automatically create the event for his calendar, and it should also sync to his device.