If this happens again. Separate them into different cages once they part ways. Keep it moist on damp paper towels. Coat it with damp powdered sugar and let him settle for a few hours. If it hasn't reinserted on its own, take a wet Q-tip and gently reinsert it. This may take two people. Then apply the band aide as suggested.

Do not use him for breeding until after his next shed cycle at the very least.

Best of luck with him.