If $ is involved then it's prob just mainly for $.
That said, one time I did have a mistress of sort and we did it one last time at her place and right after we had an argument (it was already brewing while we fucked and she said I was really hard cuz I was mad at her lol). After the fight, I went back home and never saw her again since she was leaving the country (and so was i soon afterward). Although I did keep her on chat but never chat again until recently I finally spoke to her after almost 2 years.