According to the DVD Talk review: "Sugar has been re-cut from its original R rating to a PG-13 version for its standard-def release. While these alterations are certainly minimal (a few isolated profanities and a quick shot of a porn movie playing on a hotel television), the PG-13 version does not represent the film as it was released to theaters; its creation is apparently an attempt to open the film up to a family audience. At any rate, the good news is that the Blu-ray disc presents the film in its original, unaltered form."
I'm not condoning the cuts but it does seem as if this was on the cusp of PG-13 to begin with.