Imo it`s the animation, her hip/abdomen is very bent and will most likely result in those things. Especially since it`s her and the animation that`s doing the penetration and not the guy with the plugin that afaik aligns itself.
If the talker is moving the head around alot then you can use https://hub.virtamate.com/resources/searchlight.14512/ to make the listener`s head point towards the other. If the movement is subtle then there`s that much "life" added in.
Try https://hub.virtamate.com/resources/autothruster-autogensthruster.14513/
It might be more precise than that one, I`m not sure. That phenomenon happens when there`s alignment issues such as you bending down too much causeing misalignment.