Responses
I’m not sure if it’s the right one but is it this one that you’re looking for??
https://www.mangago.zone/read-manga/retsujo_love_cross/
Yes omg you don’t know how long I’ve looking for this thank youu
it was pretty short like a few chapters long.
It was about two exes who met coincidentally at an onsen where each one went to with their current partners, and I remember the seme was with a girl, and they both cheated on their partners there