State District Judge Karen Herman told Brian Downing of Smiths Station, Ala., that he's a bully who has permanently damaged someone else's life.
Downing declined to say anything before the judge sentenced him as part of a plea deal.
He pleaded guilty in October to two counts of obscenity for rubbing his genitals on the LSU fan. Prosecutors dropped a charge of sexual battery, which is punishable by up to 10 years in prison.
The incident took place last January after Alabama defeated LSU at the Superdome to claim the BCS title.