Lovebug's story reminded me of the time when Gus was a baby and did the same thing. He figured out he could get up the stairs if he went on the side except he didn't count on my sister's dog catching him by the leg and pulling him back down.

She was very gentle but she knew he wasn't allowed upstairs so she stopped him. She also tells on him if she knows he is up to no good. If he gets in the garbage or gets too close to the unfriendly cat she goes to her mom and barks. It is pretty funny. She is spayed but would have made a great mother.