I’m quite fond of the fanon ace Jiang Cheng, but I don’t think he’d be sex-adverse, more sex-neutral to... ‘hey, if it makes you happy I’m comfortable doing some things with you specifically.’
However, I also think the man is the most touch starved human in cql and because he’s not great with human interaction he ends up being touched very rarely in a positive way, especially once Wei Wuxian is gone. It’s a part of why he’s so agitated before Wei Wuxian’s fall, he really, really, really needs his brother to give him a big hug and then walk through a market with his arm over Jiang Cheng’s shoulders, and the bastard would rather hang abandon all that for people who... aren’t him and Yanli.
By the present setting I’d say Jiang Cheng is the loneliest cultivator around, too busy being terrifying to keep his sect and nephew safe to allow anyone to get too close. Besides, he doesn’t want sex, he wants hugs, what is he a teenage girl, who would want him? (He copes with his sexuality about as well as with anything else, badly)
And then JGS dies and Jiang Cheng finds himself having to comfort Jin Guangyao because no one else is around for some weird reason, and they end up in Jin Guangyao’s rooms, drinking and talking about their losses. Jin Guangyao may even make Jiang Cheng realise what his sexuality is having grown in a brothel and that’s a strange relief, and Jin Guangyao’s hand is resting on his arm.
It’s been so long since anyone has sat this close to him, enjoyed his company, made him feel like Jiang Cheng again...
He senses what Jin Guangyao would like from him, and he wonders,
‘If I let him... will he hold me after?’