Entity Framework not mapping 1 to 1 Relationship

Question

Hi

I have some tables and I can't get them to map.

aspnet_Users
UserId<PK>
//Other Fields

Table A(intermediate table)
UserId<PK>


Table B
UserId<PK>
Field1
Field2
Field3

Yep when I add these 3 tables in I will either get a 1 to 1 relationship with

aspnet_users to Table A

or

Table A to Table B

I need to have

aspnetusers to Table A to Table B

I tried to add this association but it never works.

Error 3021: Problem in Mapping Fragment starting at line 168: Each of the following columns in TableA is mapped to multiple conceptual side properties:

How do I fix this?