The animations are jerky and thus any sexual action feels to be artificial, which is a great turn-off, because this feeling breaks immersion. Would've been cool if smoothness of movements of the characters could've been improved in animations during sex scenes.
Slippery of the textures of the bodies a problem too. It doesn't "feel" like the male character is holding a female's hand, for example, during animations. Rather their hands are just "floating" around each other, with movements of their other body parts, and not holding tightly onto each one, as it should've been.