With not a single grill mark on him, they went off to have coffee

[lxnguyen]

"So the next day, Tom was feeling the first date nerves. It didn’t help that he was picking Jane up from a restaurant where she was having lunch with her friends and he was nervous they were going to grill him. He proved his bravery once again and sat down to join them. But they showed mercy. With not a single grill mark on him, they went off to have coffee."

In the text above, what does it mean by "With not a single grill mark on him"?

Thanks

 

[Rover_KE]

Welcome to the forum, lxnguyen.

It's a forum rule that you must tell us the source and author of any text you quote.