straight man
second banana

The journalists, in effect, play straight men for one another.

"I'm trying to figure out who the straight man is."

Mark's role in season four was as a romantic straight man.

These were straight men but from the street drug world.

Either that or he was a hell of a straight man.

First, though, I had to be his straight man for a little while longer.

He walked down the street, a tall, very straight man.

If not quite the "straight man" of the group, he was certainly the most serious.