Bella Thorne's split from Mod Sun is already getting ugly, she got booted from her ex's house after she snuck in and tried to grab some of her stuff ... and the cops got involved.
Sources close to the former couple tell TMZ ... Bella waltzed into Mod Sun's Woodland Hills home unannounced Tuesday night, coming in through a back door when he wasn't home. We're told Bella wasn't supposed to be there and Mod Sun's team asked her to leave, but she got angry and refused -- so they called the police.
Sources - Bella - Mod - Sun - People
Our sources say Bella told Mod Sun's people she was just...