Neither of them were really gods, but they were the same type of beings. He has had a body before, but if it was not clear from the text it is the first time the needs of a human actually affect him.
He explicitly mentions having had sex before. just finding no satisfaction in it.
now it is stated a few times that whatever human body he has is allowing to feel the same things ase humans do.
I have not noticed it being stated by the time chapter 2 was over.
It isn't even that hard to do. just give the MC a boner and have him react with surprise at it.
noting the differences in his body.
So far, he sleeps the very first night. Then explicitly mentions not sleeping anymore shortly after when he spends all night awake in the boat watching over Rose.
He mentions multiple times how much he disdains sex. He mentioned having done it but not really being impressed by it.
When he has the slightest spark of desire for Rose... it is explicitly from the challenge of conquest instead of actual desire.
So there are multiple problems here:
1. it is rather pathetic that an immortal ancient dark lord gets "corrupted" by a human body's sex drive into liking something he previously disdained.
2. it never actually tells or shows us this is happening. even though it could easily show this.
3. MC actively disdains sex at the beginning.
It would have been trivial to just have the MC not start out asexual.
Could still have slow burn on the sex by simply having the MC be highly driven:
"My ambitions come first. I can enjoy myself later"
If it was not complaining, then I apologize. I am not the greatest at this language, and I wrote it in the middle of the night when I already was a bit agitated.
Alright. fair enough.
I should note, back then I was asking...
NOW I am complaining