We had a mutt who didn't fake limp, but she'd fake shiver (''ooh, it's winter, let me in!") to get inside.
My parents deck can be seen from inside the house on 3 sides to various windows/sliding glass doors. The dog would stand at the dining sliding glass door, looking inside with big puppy dogs eyes, shivering. If she wasn't let in and whomever she was looking at left the room, she'd stop shivering, which you could observe from other windows in the house. =)