Gay men and straight women might not be amused. And straight guys be embarrassed doubly, first for having to call the plumber and secondly for actually looking at a guys crack...
I'd rather, there be an arrow pointing up saying something like
"My eyes are up there (on the other side)"
We had an incredibly sweet/hot young guy who 'did our plumbing' at both the office and home and I used to try to think of plumbing problems in order to have him come and do work.
He had the sweetest/hottest little plumber's butt I ever did see and I think he may have put it on display on purpose.......I think though that he was our favourite because he loved our cats and listening to the classical music we have on all day for them when we're not around.......