think i found another fic that matches to the one i was looking for
it`s a little bit closer to what i remember
story wise.
Golden Cage by Stella Mira
When you are faced with a difficult choice, most often the mind will arbitrarily decide based on what feels familiar. A single mistake can irrevocably change one’s entire future. A woman is forced to face this harsh truth as she struggles between her lingering feelings towards her first love and her growing attraction towards his elder brother.
rating ma
author is known as Millarca on Archive of our Own as well
archiveofourown.org/works/778594?view_full_work=true
but yeah took awhile to find