Are Sandra Bullock & Jesse James over? A tattoo model named Michelle "Bombshell" McGee claims she and the "Monster Garage" star had a sexual affair while Sandra was in Georgia filming "The Blindside".

According to McGee, "We ended up on the couch. He wanted to watch movies, but I asked him, 'What's going on with you and Sandra?' He said, 'She doesn't live here. She has a house in Austin. She is filming, and I can't talk about it.'...We had intimate relations."

Insiders say that Bullock has already packed her bags and is living in temporary housing until the matters are sorted out. She's also cancelled her appearance for the London premiere of her movie... and James shut off his Twitter account last night. Yeah... that's not good...