i recommend link and ring, they are college students but still show a lot of maturity within their relationship. Boku no Omawarisan is also really good and the characters are both older (30 and 40 i think). And Boku no Papa to Papa no Hanashi is good too, the characters are both older adults and have a kid (no mpreg, no omegaverse), lots of maturity from both of them. Lastly Our Not So Lonely Planet Travel Guide, both older adults and have alot of maturity with their relationship, especially later on when they feel more confident expressing their relationship :)
Hope this helpedddd~
thankyou! youre one of the Yaoi's Angel
no problem lovely, glad to help!! <3
is there other stories outh there lile this one? I want a mature couple like them