Movie is most probably softcore porn but there was some story going on, I watched it on tv somewhere around 2005.
I suppose smaller budget, kind of cable tv channel erotic thriller.
I remember a scene where couple goes to a hotel room to do some briefcase exchange(or steal) with stereotypical fat American guy (kind of redneck accent).
Anyway they start arguing and fat guy calls for help, and they smack him in the head and he falls down unconscious.
They assume someone from hotel staff heard it, guy hides. Girl quickly sits on the unconscious fat guy, takes off her black dress (no underwear), and stars moaning and pretending she has sex with him. Staff guy opens the door sees them “having sex” and goes away (not much surprised that fat guy fucks super hot brunette).
I think there was some murder at the beginning of the movie. And that there was another couple (30-40s) the ones from scene I described were in their 20s.
Girl had dark long hair (I was searching for softcore porn actresses in the 90s-00s could be Gabriella Hall) and was wearing short black sundress. I think that her boyfriend had medium hair combed to the side/back.
Tittle was translated as “rough game”.