How to compare data from two models in Modelform Django

Question

I'm creating an ebay like auction site where users can bid on an item they like and if the bid is higher than the last bid, the bid amount displayed would update to the newest bid.

I want to run validation on the modelform to compare the first amount (that the person that created the listing) inputted with the last bid (that the new user inputted).

The problem is that they are in two different models and I'm not sure how to validate both without an error

FORMS.PY

class BidForm(forms.ModelForm):

    class Meta:
        model = Bids
        fields = ['new_bid']
        labels = {
            'new_bid': ('Bid'),
        }


    def clean_new_bid(self):
        new_bid = self.cleaned_data['new_bid']
        current_bid = self.cleaned_data['current_bid']


        if new_bid <= current_bid:
            error = ValidationError("New bid must be greater than the previous bid")
            self.add_error('new_bid', error)
        return new_bid

MODELS.PY

class Auction(models.Model):
    title = models.CharField(max_length=25)
    description = models.TextField()
    current_bid = models.IntegerField(null=False, blank=False)
    image_url = models.URLField(verbose_name="URL", max_length=255, unique=True, null=True, blank=True)
    created_at = models.DateTimeField(auto_now_add=True)
    category = models.ForeignKey(Category, max_length=12, null=True, blank=True, on_delete=models.CASCADE)
    is_active = models.BooleanField(default=True)
    user = models.ForeignKey(User, on_delete=models.CASCADE)

    def __str__(self):
        return self.title

    class Meta:
        ordering = ['-created_at']


class Bids(models.Model):
    auction = models.ForeignKey(Auction, on_delete=models.CASCADE, related_name='bidding', null=True)
    user = models.ForeignKey(User, on_delete=models.PROTECT, related_name='bidding')
    new_bid = models.IntegerField()
    done_at = models.DateTimeField(auto_now_add=True)

VIEWS.PY

@login_required
def make_bid(request, listing_id):
    auction = Auction.objects.get(pk=listing_id)
    user = request.user
    if request.method == 'POST':
        bid_form = BidForm(request.POST)
        if bid_form.is_valid(): 
            new_bid = request.POST['new_bid']
            current_price = Bids.objects.create(
                listing_id = listing_id,
                user = user,
                new_bid = new_bid
            )
            messages.success(request, 'Successfully added your bid')
            return HttpResponseRedirect(reverse("listing_detail", args=(listing_id,)))


        else:
            bid_form = BidForm(request.POST) 
            return render(request, 'auctions/details.html', {"bid_form": bid_form})  
                
    return render(request, 'auctions/details.html', bid_form = BidForm()) 

DETAILS.HTML

                            <p>{{ detail.description }}</p>
                            <hr>
                            <p>Current price: ${{detail.current_price}}</p>

                            <form action="{% url 'make_bid' detail.id %}" method="post">
                                {% csrf_token %}
                                {{ form.non_field_errors }}
                                {{ form.errors }}
                                {{ bid_form }}
                                <input type="submit" class="btn btn-primary btn-block mt-3" value="Place bid">
                            </form>

I'm having this error

KeyError at /make_bid/2

'current_bid'

Request Method:	POST
Request URL:	http://127.0.0.1:8000/make_bid/2

I'm sure its because I'm trying to compare two different models, but don't know a better way to do this. Could you please direct me or is there a better way to run this bid validation process?