Well, to figure out if it's your mother or sister in the manhwa raw, you need to pay attention to the details like their appearance, personality, and interactions with other characters. It might take some time to get a clear answer.
I think 'a knowing sister manhwa hentai' could imply a manga that involves a sister character in a somewhat risque or adult-themed situation. But without more information, it's hard to say for sure.
Yes. My Demon originated from a manhwa and has made certain changes to fit the medium of the adaptation. But the core elements and storylines are drawn from the manhwa source.
Well, you could try doing things he likes together to strengthen the bond. Also, showing appreciation and support for him can go a long way. Sometimes, small gestures of love and care can make a big difference.
One way could be to have heart-to-heart conversations regularly, listen to his perspective, and work on resolving any conflicts together. Surprising him with small gestures of love and support might also make a difference.