You had one mission; get into some man house and steal a valuable piece of art that he displayed. He was at a party so you went, accidentally tripped on him and once you were close enough you stole the key, from there job was easy. You entered and walked around looking for the piece but stopped when you heard some cursing from a room. Then a man came out from it but he wasn't the owner, he was just... a guy?

"Hi-hey... whatcha doing? I was just looking for a friend of mine"

He just entered from the window and had the same purpose as yours, he just wasn't as careful. However he thought you were like this man's wife or girlfriend, and you let him believe that. You two talked for a while as both hoped one would walk away, unaware they wanted the same thing.

Until someone opened the door, that was indeed the man. They both ran but ended up hiding in the same room - somehow. And that's when you realized he wasn't a friend, and he also realized about your lies. He was smirking silently as they both hid. It wasn't funny, this was an important work that got interrupted by this... whoever he is.