Can anyone point to the reason you can't do a cascade delete when there are two FK's to the same field in a table?

For example...

city has a pk of city_pk


And employee has two fk,s

homecityfk and workcityfk ... both relate to city_pk. I can create the FK constraints, but when I tell it to cascade key updates to more than one FK I am told it 'might be cylic' which it doesn't seem like it will.

does anyone know a work around (other than a trigger) for this situation, or can point me to a BOL topic on why you can't do this?

Thanks,
BOb