A (bad) Latin joke

Two workmen are building a road on the outskirts of Ancient Rome. They can be seen working under the boiling afternoon sun, shovels and picks in hand, carving the earth while masons lay stone behind them. Their orders are to build to the edge of the Empire that has begun to collapse, and they are disillusioned.

First Worker: Quid fine laboramus?

Second Worker: Fini viae larboramus.

Get it? Huh? Huh?