Sources familiar with what went down told TMZ Stanton was partying with friends at The Encore for a co-ed bachelorette event.
Law enforcement reported security came to the room for a noise complaint, and Amanda's boyfriend Bobby was talking to the guard. We're told that's when an apparently drunk Amanda tried to get between them, and shoved Bobby.
We're told the shove was hard enough for security to call cops, who arrested Amanda for misdemeanor domestic violence. She was released Monday.
Sources close to Amanda tell us she and Bobby are still together, and they both think someone slipped something into her drink.