Reverse SQL Server Listener?
Check out this article on MSSQLTips.com on how to configure readable secondaries and read-only routing in SQL Server 2012 AlwaysOn Availability Groups.

Basically, as long as you're only doing read workload, you enable readable secondaries and set up routing in your AG and any requests with Application Intent=ReadOnly in the connection string will connect to the secondary and perform its read workload there.

If your application needs to do any write workload, it must use a different connection that does not specify read-only intent in the connection string otherwise it will error when trying to perform the writes.

Also, make sure you validate your licensing scenario to make sure your secondary is properly licensed for performing read workloads.