Hi, I'm looking for manga that depict BL/GL relationships from an outsider's POV, like a friend, family, total stranger, etc.

Bonus points if:

• The story is BL from a girl's perspective or GL from a guy's perspective (ie. Joshi BL)

• The story is from a child's POV (ie. The Komukai Household's Circumstances)

That's my only critera - I'm fine with manhua or manhwa, explicit scenes, and oneshots. Thanks in advance! (:

I really like this one—it just got licensed! It’s from the parent’s perspective:
My Son Is Probably Gay

Edit: These might work as well! (I hope you see this, I'm sorry it took me 2 days to edit instead of 1 haha ^^)
Renai Flag Zero Joshi no Meisou- I haven't read this one, but from what I've seen it's an over-the-top parody from the girl's perspective. Everyone she likes ends up in a BL relationship.

Gin no Kutsu- From the son's perspective, but not really romance-focused.

Watashi wa kabe ni naritai- Haven't read this one because it seems a little sad, haha. Unrequited love isn't my favorite trope 😉

My Brother's Husband- Doesn't focus as much on BL relationships themselves, per se, though that's a key factor.

These two are about friends finding out their classmates/friends are interested in the those of the same gender:
Kare no Aijou no Hakari- Has some similarities to Joshi BL

because the protagonist falls in love with a boy who doesn't like her back.

Sorairo Flutter- Fair warning, I actively disliked this. But I do think it fits your criteria: the main character learns that his classmate is gay, and learns more about him (and his own sexuality as well).

Hare no Hi
From a father's perspective