Are you the author or something? Jesus, stop trying to excuse this lame ass sex scenes. Forced sex still can be exciting to read and if this is a problem for you to understand then you don't understand why toxic yaoi is popular. And this is why this is becoming a flop manga despite S1 being so popular. Their sex scenes or r*pe scenes if you will are boring.
Pretty sure the lack of chemistry is intentional. It’s pretty clear Rian and Lorenzo have wildly different tastes in bed (being a loving partner vs. being a sadist). Part of their relationship progression will probably be figuring out the bed situation and compromising. It’s not like Hanse doesn’t know how to do smut, the ones in Red Candy were pretty decent imo.
I like seeing the sexual incompatibility cause in every other BL they’re perfectly compatible from day 1.

But dear go their sex is still boring and lacks chemistry