class Request(models.Model):
    title = models.CharField(max_length=500, help_text="The name of your request")
    .....
class VM(models.Model):
    request = models.ForeignKey(Request)
    ....
class Interface(models.Model):
    interface = models.ForeignKey(VM)
    .....

class NetPartinline(admin.TabularInline):
    model = Interface
    show_change_link = True
    extra = 0
class vminline(admin.StackedInline):
    model = VM
    show_change_link = True
    inlines = [NetPartinline,]
    extra = 0
@admin.register(Request)
class RequestEditor(admin.ModelAdmin):
    ....
    inlines = [ vminline ]