resolving foreign key asymmetries in a data model to reduce reliance on FromSqlRaw

Question

simple example here:

public partial class human_being {

public int id {get; set;}
string first {get; set;}
string last {get; set;}
}

public class alienhuman {

...
public int alienID {get; set;}
[ForeignKey("activity")]
public int alienActivityID {get; set;}
public activity activity {get; set:}
...
}

and

public partial class activity {

/* a bunch of things */
public int ID {get; set;}
[ForeignKey("human_being")]
public int[] thx2048_humans {get; set}
/* this is where i am in a tizzy! this line below is commented out due to the issue described below */
public ICollection<human_being> whataTWISTEDobjectname {get; set;}
...

[ForeignKey("alienhumans")]
public ICollection<alienhuman> alienhumans;

}

now, if i pull the data for activity, i have no problem getting the integer array with the ids of each human_being.

similarly, i have no problem getting the collection of alienhuman objects since, i assume, there is a symmetric relationship between the keys:

//assume holderObject.ActivityCollection has successfully been assigned a collection of activity objects.
//these two lines work fine.
var localActivityObject = holderObject.ActivityCollection.SingleOrDefault(<some condition>);
await _context.Entry(localActivityObject).Collection(x => x.alienhumans).LoadAsync();

however, i would like to use this API to get the human_being collection as well, but:

await _context.Entry(localActivityObject).Collection(x => x.whataTWISTEDobjectname).LoadAsync();

perhaps "expectedly" fails, since this call tries to look for the column associated with activity.ID in human_being, which does not exist.

am i simply resigned to using FromSqlRaw unless i want to introduce unnecessary relationships?

keep in mind i'm new, so forgive me if i'm overlooking something.