This visuals included in this mod are static. When you load the mod it will set the male character's penis size and skin tone to suitable values. If you change them then you'll encounter visual discrepancies.
If the male character's skin is dark then you'll still see a light-skinned penis inside her mouth. If the male character's penis is narrow then you'll still see a thick penis in her throat. If you use a mod which replaces the guy with a horse then you'll still see a human penis in X-Ray mode.
Due to the way that SDT's layers are composited, this mod will not cooperate with overlying clothing (such as collars and shirts). This mod works best when the girl is nude.
The mod does not include visual effects for swallowing or ejaculation. You won't see semen flowing down the girl's throat in X-Ray mode.