I saw a tweet about this and added it to my wishlist immediately without looking into the dialogue too much (I have a harder time reading things digitally). Turns out the old men speak in the Kansai dialect. I have had an amazingly bad time trying to understand the stories lmao.
「じじいの恋」is a collection of stories that are honestly more seinen than BL. It seems to be published under the Kurufune pixiv branch of libre, but most of the stories did come out in the Be x Boy magazines, so it is BL? Anyway, it's closer to what you might expect from Fumi Yoshinaga's josei stuff or maybe Gengoroh Tagame's ventures into non-geicomi works: there are queer elements, but the romantic depictions are pretty thin. I guess it makes sense since Jijii no Koi is mostly gag related?
Anyway, it collects 4 stories:
The titular Old Men Love, a story about a kid learning that his dad's friend is actually his lover (おとんとてっちゃん) , a story about a mangaka who has never been in a relationship and whose works are informed by his lack of experience (お兄ちゃんとメロリーナ), and a salary man who has communication issues and no friends (斉藤くんはめどくさい).
There's a lot of kanji so it was really hard to read for a child like me (thank you, translating software). But I did my best because I did find the stories funny and the things they say about (pls don't laugh at the words I'm gonna use) the human condition is at once relatable and comforting.
There are stuff like how Takurou's obsessive love for Genta wasn't enough to make him defy his familial responsibilities (he says love and household are different things, which is a punchline to a joke in the story but also in some cases, very true). A young boy who finds that he, his dad, and his dad's male lover can actually be a family even though his biological mother left ages ago for another man. This is one of my favourites because it shows stuff like Teppei going with Shouta to buy new clothes and when asked what his relationship with Shouta is, they say different things (Teppei says 'older brother', but Shouta says 'dad'). Saitou is the type of quiet guy with communication issues (he doesn't own a mobile phone and uses only the company provided phone), gets bullied by his workmates because he can't express himself easily, and makes his first friend in Kirino.
They're messy and a lot of them have a hard time forming bonds with people and the stories focus on how they do it. I liked this a lot.