Possible Clues:

• Provision for late-arriving spectators (2 words)
• Provision for late-arriving spectators
• Seeking office space - what's left due to high turnout
• Substitute with bride provides space for late arrivals, perhaps
• Emergency choice as husband finds nowhere to sit
• No place on bench if just this man of the match substituted?
• No seat available for the wedding substitute
• Where people won't five down, is his cue 'I won't'?
• No seats available for replacement husband-to-be
• Spillover space, or a wedding sub?