More details have emerged about the arrest of Paris Hilton's new model boyfriend River Viiperi in Las Vegas on Monday morning.

The reality star and River were partying at SX nightclub at the Encore hotel in Las Vegas, when Paris reportedly locked lips with another woman. River allegedly punched the girl's boyfriend, who wound up needing medical attention.

River was arrested for misdemeanor battery but wasn't taken to the police station. According to TMZ.com, the incident is still under investigation.

Meanwhile, Paris retweeted on Tuesday, "RT @HurricaneCari: Best vegas trip yet!! thank you @ParisHilton @ChadsTracks @RiverViiper @barronhilton @VanessaDuBasso @mgmgrand love u."