How to add a repeated foreign key in the same model - asp.net-mvc

Question

I am working in an ASP MVC project, which uses MvcScaffolding a lot, I have a project and a client model, the thing is that the project has to be relationed with client model in two ways (Billing client and Service Client, and both data are from same client model)
I have no idea how to do this, here are my models
Client Model
public class ClientsX
{
[Key]
public int idcliente { get; set; }
[Required(ErrorMessage = "A Legal ID is required")]
[StringLength(150)]
[Display(Name = "Company Name: ")]
public string CompanyName { get; set; }
[StringLength(150)]
[Display(Name = "Legal ID: ")]
public string LegalID { get; set; }
[Required(ErrorMessage = "A Contact First Name is required")]
[StringLength(150)]
[Display(Name = "First Name: ")]
public string FirstName { get; set; }
[Required(ErrorMessage = "A Contact Last Name is required")]
[StringLength(150)]
[Display(Name = "Last Name: ")]
public string LastName { get; set; }
[Required(ErrorMessage = "A Contact Email Address is required")]
[DataType(DataType.EmailAddress, ErrorMessage = "Please enter a valid email address")]
[EmailAddress(ErrorMessage = "Please enter a valid email address")]
[StringLength(150)]
[Display(Name = "Email Address: ")]
public string email { get; set; }
[Required(ErrorMessage = "A Phone Number is required")]
[StringLength(15)]
[Display(Name = "Phone: ")]
public string phone { get; set; }
[Required(ErrorMessage = "An Username is required")]
[MaxLength(50, ErrorMessage = "Your Username cannot exceed 50 characters")]
[RegularExpression(#"^[\S]*$", ErrorMessage = "No White spaces are Accepted")]
[Display(Name = "Username: ")]
public string username { get; set; }
[Required(ErrorMessage = "A Password is required")]
[DataType(DataType.Password)]
[Display(Name = "Password: ")]
public string password { get; set; }
}
Project Model
public class Project
{
[Key]
public int idProject { get; set; }
[Display(Name = "Billing Client")]
[Required(ErrorMessage = "This Field is required")]
public int ClientsXId { get; set; }
[Display(Name = "Client")]
[Required(ErrorMessage = "This Field is required")]
public int ClientsXId { get; set; }
[Display(Name = "Status")]
[Required(ErrorMessage = "This Field is required")]
public int estatusId { get; set; }
}
Yes, I know ClientsXId is repeated, but is on purpose, because I need to have the same data in the project model, but it gives me this error:
Error 5 The type 'SSMS_2._0._1.Models.Project' already contains a definition for 'ClientsXId' D:\PC\Visual Studio 2013\Projects\SSMS-2.0.1\SSMS-2.0.1\Models\ProjectModel.cs 99 20 SSMS_2._0._1
How can I make this work?