A method for future reference is something like this. bannedphraseform is the first form and expectedphraseform is the second. If the first one is hit, the second one is skipped (which is a reasonable assumption in this case):
if request.method == 'POST':
bannedphraseform = BannedPhraseForm(request.POST, prefix='banned')
if bannedphraseform.is_valid():
bannedphraseform.save()
else:
bannedphraseform = BannedPhraseForm(prefix='banned')
if request.method == 'POST' and not bannedphraseform.is_valid():
expectedphraseform = ExpectedPhraseForm(request.POST, prefix='expected')
bannedphraseform = BannedPhraseForm(prefix='banned')
if expectedphraseform.is_valid():
expectedphraseform.save()
else:
expectedphraseform = ExpectedPhraseForm(prefix='expected')