"Union Plumbers" joke

A plumber was called to woman's apartment in New York
to repair a leaking pipe. When he arrived he was pleased to
discover that the woman was quite a luscious, well-stacked
babe, and during the course of the afternoon the two became
extremely friendly.
About 5. 30 p. m. the phone rang, disturbing the bedroom
shenanigans. "That was my husband," she said, "He's on
his way home, but is going back to the office around 8.
Come back then, dear, and we can take up where we left off."
The union plumber looked at the woman in disbelief.
"What? On my own time??"