Nobody likes to be asked about their alleged infidelity after a long flight!

Patrick Dempsey returned to LA on Monday after coming in second at the legendary Le Mans 24 Hours auto race in France, and the actor was peppered with questions about his alleged affair with a Grey's Anatomy staffer as he made his way to the car to leave the airport.

Although he chose not to comment, his answer is written on his face! The Hollywood hunk seemed annoyed and tense, and we have a feeling we might have hit a hot button! The TV star was suddenly fired from his hit show in April, just a few months after his wife Jillian Fink filed for divorce. Reports soon began circulating that Patrick was sleeping with a young woman that worked on-set, and the odd timing of events certainly didn't quiet the chatter.

"It was obvious to everyone Patrick was [sleeping with] her. It got very messy and emotional on set and became a huge liability. Patrick would remain in his trailer after hooking up with her on set and refuse to come out," a source dished to Radar.

Maybe he just took his role as a doctor too seriously and was giving complimentary check-ups to the woman in question?! NOT!