Multiple NICs / Multiple Default Gateways

I have a few VMs that have dual NICs (say NIC1 and NIC2).  Initially, in Windows, I'm only assigning a default gateway to NIC1.

In my IP Customizations (under Network Mapping) I have it setup to NOT assign a gateway to NIC2.  I left it blank.

However, after a test or failover, it still ends up assigning a gateway to NIC2.  And, because of this, Windows and my application get confused on which NIC to egress.

My current workaround is to assign NIC2 a higher metric. 

Has anyone else seen this problem?  This a bug or how it's intended to work?

Thanks in advance for your help!