animated games with pre-insertion (I don't know if this is how it say, I'm not an English speaker), it generates a sense of expectation that when consummated, makes it much better. A concrete example would be the penis being pressed against the vagina slowly until it enters only the tip to this follows a little movement with the tip to finish with a full insertion and from there begins the animation of common sex. Can also be sets that control penetration and speed manually.