In their comedy duo, he's always the straight man.
В их комедийном дуэте он всегда выступает вторым номером.
Definitions
A 'straight man' is a term from comedy referring to the person in a comedic duo whose role is to set up jokes and react in a serious or deadpan manner, allowing the other person (the 'funny man') to deliver punchlines or act humorously. The straight man provides contrast and makes the comedic moments more effective.