Both tongues busy at once
Head to toe in lesbian 69, each woman has her tongue in her partner's pussy and her partner's tongue in hers. Nobody waits for a turn, so giving and getting blur into one long, shaking loop.
On top, side by side or across the bed
The classic version puts one woman on her back and the other on all fours above her, knees by her ears. The one on top controls the depth with her hips, and the one below gets a view of her ass while she licks. Side-by-side 69 is gentler: both lie on their sides with a head resting on a thigh, which makes it easier to last. At the edge of the bed, the woman underneath lies across the mattress with her head tipped back, which opens the angle for fingers. The position grows out of full facesitting once the rider leans forward.
Sound changes in a lesbian 69, since every moan is muffled against a thigh. The camera works from the side to catch both faces, or from behind the woman on top. Unlike regular oral, where one woman watches the other enjoy it, neither partner sees much more than skin. The good part is the moment one woman loses her rhythm because she is about to cum, and her partner keeps going anyway. Starting with a slow make-out gives that ending a long run-up.