Paris Hilton is allegedly dating River Viiperi.
River Viiperi was arrested early Monday for battery after allegedly decking some guy ... whose girlfriend was making out with Paris in a Las Vegas nightclub.
River Viiperi was arrested for battery after a male club-goer filed a report.
Claiming his girlfriend was "making out" with Paris inside XS nightclub at the Encore hotel, the alleged victim says River, a 21-year-old model, hit him in the face.
Hard enough that he sought medical attention, according to the recipient.
River apparently didn't like seeing his GF suck face with another girl. Odd.
The victim told hotel security he wanted to press charges against River, and when Las Vegas police arrived to the scene, Viiperi was arrested for misdemeanor battery.
He was cited and released without ever going to the police station.
Paris has not been accused of any wrongdoing, except possibly dating some 21-year-old hothead named River Viiperi. And the whole anti-gay rant thing.
[Photo: Pacific Coast News]