Richard Hilfiger

Tommy Hilfiger's son is free to exhale a smoky sigh of relief -- because TMZ has learned he won't be prosecuted for his felony weed bust. As we first reported, 20-year-old Richard Hilfiger -- who dabbles is rap music -- was pulled over in West Hollywood in July ... when cops allegedly found a fat…

TMZ has learned Tommy Hilfiger's 20-year-old son was busted for weed ... and cops think the rapper intended to sell the stash. Law enforcement sources tell TMZ Richard Hilfiger -- who recently cut a track with Kid Cudi -- was pulled over last weekend in West Hollywood by Sheriff's deputies who…