Kristen Stewart Apologizes for Cheating on Robert Pattinson: I Love Him; I'm So Sorry

Kristen drove from the seedy part of town to a more scenic spot, parking at a viewpoint overlooking the HOLLYWOOD sign.

Us says they stayed in the car, "slouched down and kissing like teens." They eventually emerged to take in the vista, and Sanders, who, let's face it, is old enough to know better and has much more to lose in this scenario, "embraced [Kristen] from behind and caressed her hand and side."

Whenever anyone approached, the two would break apart and head in opposite directions.

"He seemed more cautious," relays an eyewitness. "She was lost in the moment. It was clearly all she was thinking about."

Eventually, they returned to the car for 20 more minutes of together-time before zooming off. According to Us, Stewart dropped off Sanders three blocks from his family home, where he lives with Bell and their two kids, who are 7 and 5.

Speaking of Sanders' missus, her recent online activity is under scrutiny in the wake of the scandal. Find out why …