After the auction was over, Chris exited the hall alone. He didn't leave alongside the girls because he had things to do and it was best they weren't here when he did that.
He said his goodbyes to the girls inside the VIP room and left the room just before the final item's price was finalized.
Once the final item was sold, there was no reason for people to stay in the auction house and everyone would leave almost at the same time. This would make him lose his prey for the night.
He didn't want to lose track of them, so he left the auction a few minutes before others and waited outside for the two guild masters to leave.
Once he found them outside, he slowly followed them. They both kept their distances to keep up with their appearances. They didn't want to take chances of others finding that they were in cahoots with each other.
He marked both of them, so that he won't lose them and followed Novah first.