Hugh Hefner's Son -- Sentenced to Violence Classes After Alleged Playmate Beating

Hugh Hefner's son Marston has been sentenced to a 52-week domestic violence program after allegedly beating his Playmate girlfriend Claire Sinclair last month.

Marston was charged with corporal injury on a spouse or cohabitant after the February 12th incident -- when he allegedly attacked Claire at the couple's Pasadena apartment, bruising her up and damaging her laptop. He pled "no contest" today.

Marston was charged with vandalism over the laptop -- but that count was dismissed.