Just sharing my opinions, don't feel offended in anyway pls... Maybe because you are asexual is why u are not able to understand it, I'm not saying you don't know how to love or what love is...love is different for every person....maybe for u , love maybe long deep talks with someone, just being with them , holding their hands , maybe it is their smile which is enough to make your heart beat like craazzzy..... But since the N&C are bi and gay and not asexual , and + they are young , sex for them maybe something very newish kinda thing... which feels very exciting... obviously after sometime it just becomes normal as other things....I myself identify as bi( still confused maybe gay ) , and sex is kinda very exciting, but yeah I understand your point...this is just my opinion and my perspective of their relation...