Is it this one? it's pretty similar to your description
https://www.mangago.me/read-manga/this_time_i_will_definitely_be_happy/
i forgot about this manga until now, i went thru my whole reading list to find it omg
the title is "This Time I Will Definitely Be Happy"
Yes yes! Thank you!
Yes! Thank youuuuuuuuu! ╥﹏╥
Happy reading!
Help please, this manga has been on my mind for days and can't find what it was. It started as hero ml went away to subjugate demon king so fl went to capital to work since she's been reincarnated multiple times and already know the ending since she thought hero ml will marry the princess. Key points are the hero ml and fl has been reincarnated multiple time in different bodies. And the first gen hero ml turned out to be the current demon king after the first gen fl got sacrificed by the kingdom. Help huhu