Susan Elizabeth Shepard and Charlotte Shane offer up a feminist critique of the 69 position:

Further examination of 69 confronts us with an unfortunate truth: it is a distinctly capitalistic, efficiency-emphasizing endeavor that erases the unique personhood of each participant by relying on a crude approximation of how human bodies fit together if human bodies are conceived of as identical, two-dimensional figures like the numbers of its name. While it is possible that two bodies might be so perfectly proportioned that, when flipped to be positioned feet to head with one another, the genitals and face align perfectly, a cursory survey of most human bodies would testify to this supreme improbability. Height alone is not the issue but rather distribution of that height along someone’s torso. Contortion will almost always be required of the neck and larger spine, creating an oft-unsustainable and painful form that dooms the experiment from the start....

The position also echoes the service economy in its demand (mainly on women) of a convincing performance of pleasure. It's not enough to simply be present and to competently do the job that's asked of you by your lover, you must also appear to simultaneously enjoy said lover's ministrations, regardless of the delicate balancing requiring to keep from suffocating him or breaking his nose. This is a form of emotional labor like that demanded from baristas, servers, and sex workers; not only do you have to do a good job, you have to like it.... Inevitably, a man such as this will make a great show of this request testifying to his “love” of “pleasing” a woman. You are well within your rights to ask such an individual, “if you are so mad about eating me out, why can you not give it your full attention? Why must my nose in your balls be the carrot before the horse?”

My money is on parody. But in the era of #CancelColbert... who the fuck knows?