Possible Clues:

• (Oh, my!)
• First bit of stomach fits into opening? Let out pants
• React to a twist ending
• Talk then quietly catch one's breath
• Struggle to breathe
• Expression of shock
• [Surely you can't mean ...!]
• Breathe in sharply when embraced by doctor
• [What a shocking thing to say!]
• What the comedian produces in front of park comes as a shock