Sort of inconsistent. If you find the magic words to make the mouth be behind the pussy, do share.

Trigger phrases are something like:

"a close-up of {woman} performing cunnilingus."

"{her} head is between two legs" pretty important

"{She} is licking/eating the crotch." gives me more consistent mouth on pussy

You can swap out "woman" for what ever. It's harder to change the legs, but it can be done if you are lucky.