How big is that big tho? I recommend Dash (its manhwa is ongoing with only few chapters) but its novel is completed with side chapters and is accessible online. They have 8-year gap and they first met when they were underage but dw, they reunite when the seme was already at legal age. Also, its an omegaverse.
hello! here are two of my favs
https://www.mangago.zone/read-manga/dangerous_convenience_store/
https://www.mangago.zone/read-manga/on_or_off/
^^ this one starts off kinda rough unfortunately but the redemption arc is rlly good :))
Oh sorry, you meant older seme. The uke in here was older tho. Mb
How Sweet is a Sugar Daddy
https://www.mangago.zone/read-manga/how_sweet_is_a_sugar_daddy/
Hi, any recommendations for yaoi with a big age gap, preferably older seme. No underage uke please. Thankss