This one is mine, so it's not great, but I like it....
A guy named Bob works in an oil refinery, and since he only lives about a mile from the plant, he just rides his bicycle in every day. There only inconvenience is he has to carry his bike across a catwalk that stretches over numerous vats of oil being refined.
One day, he stumbles and *gloop...
My wife says she's too fat to be on the catwalk.
"You're a roll model," I told her.
My father wanted me to be a firefighter
So he installed a brass pole from my bedroom to the living room. It didn't work. But my sisters both work at the Catwalk