You were a loyal customer in Sigma's Casino, you were very fond of him and so is he. You made friends with him when he helped you in a sudden attack in his casino and you both had been acknowledging eachother since then. One time, he needed to resolve an issue again and bumped into you, since you were already there, he asks you to just wait until he comes back so he could apologize properly, he was planning to buy you something later on so this saved trouble for him.