Did the mother know?

I felt it was implied she did know or at least sensed it. It was a fortnight ago I saw it now, but as I recall, she said she was jealous of Richard and his closeness to her son and, well, obviously no-one has told her and it definitely isn't 100% clear either way.. but my feeling was that even if she hasn't specifically acknowledged it to herself, she understood even when Kai was still alive that Richard was more than just a friend to Kai. And this was, as she admits (not to Richard, but for us) the source of her dislike for him - that she was jealous of their emotional relationship. However Kai hasn't come out to her and Richard would not do that to Kai or to his Mother after his death.

If Junn truly didn't know when Kai was alive though, although he never tells her, it's surely clear to Junn by the end of the film after the time she has spent with Richard and what he does for her.... I would have thought.

[deleted]

I'm pretty sure she had an inkling of Kai and Richard's relationship, but was a parent who wanted to leave it up to her child to be open about it (or in this case, Richard breaking down and airing out all their laundry).

Women are born with a sixth sense. That sense is to be able to read people to protect their children from danger, etc. So this Asian woman had that sixth sense especially if she's chosen to, it seems, remain away from the world so she doesn't or isn't reminded of all she does know. I don't think she didn't know. She knew but wanted to hold out hope. Granted I haven't seen this yet, but with two men taking primary interest in her after her son passed with them there not just to console her but for more about Kai, her son, with them apparently withdrawing questions to spare her heartbreak or heartache that her intuition was spot on IMHO.

So does she "know" by the end of the film? Or do they leave it ambiguous?

GFW ✨

There are mothers who may suspect that there is something unusual about their son. It may flit across their minds (IF they are conscious of that world), but is often dismissed as "No, that's not possible with MY son". Even mothers who have some inkling that such relationships exist are prey to the usual stereotypes and cannot believe that if their son is not flamboyant, then he can't possibly be gay. It's tied up with the way that different cultures view homosexuality. Had she been European, I would have said "Yes, she at least suspected it". In her case, I'm not so sure.