Acting suspiciously
He didn’t usually behave in such a shady manner. Although they hadn’t exactly decided to be exclusive in these latter months, he had always trusted Sarah, and she had always given him the reassurance that she wasn’t seeing anyone else. That explains why John was so enquiring. It was plain illogical.
Waiting for someone
After a while of Sarah being in his path, she eventually stopped. She waited while seated on a park bench. While hiding behind a tree, John continued to monitor her every move. It was clear to John that she was waiting for someone because she didn’t have a book or anything else to occupy her time. And who?