Aziraphale was tense the entire time the man was touching his book. A sigh of relief escaped him as it was slid into place. It was less the fact that an unknown, vulgar man was touching his things, but rather the thought that he might actually want to buy it.
Aziraphale might run a bookstore, but he seldom had interesting in selling any of the books there. They were his, his treasures. He had more than once searched his soul, and his bibles, wondering where this fell in the list of forbidden vices. Considering he was an angel, such things were even more important. Usually, he found a reasonable excuse for continuing to hold on to material possessions.
Despite the fact that the book had been placed back, Aziraphale little relaxed. The man was still here, and so was the temptation.
"You've been to Ireland, have you?" Keep him distracted, maybe lead him toward the door. That was the plan, anyway.