Well, he has two options: either stop lying to himself that sex is bad and the second option is to avoid playing games like BG3. I'm pretty sure that he's just a hypocrite like most religious people and will be playing the game anyway even if Larian adds 10 minutes of non-stop sex in it. If he's a real honest prude then he will be in such minuscule minority that it won't reflect on the game well-being in any way.
They are actually being very reasonable in stating the difference between what they would like and what they understand is probably going to happen, and asking politely if there can be a way to avoid it. Lumping GM4Him in with the OP who states repeatedly that sex has no place at all in BG3 because it wasn't in BG1 & 2 (it was) or DnD (it is) is neither fair nor productive, and your tone of response was neither enlightened or respectful; and almost expressly designed to get another thread on the topic closed down.
