Question about VPC loops

Hi guys,

We are planning to implement the linked topology. As you can see on the picture below, there will be 3 N5K pairs in separate VPC domains, connecting to both 6500s.
Our concern is whether there will be an L2 loop in our topology or not (without using STP of FabricPath!)?
Can anyone advise on this design? We'd like to avoid using STP or FabricPath!

Our design plan

Thanks