After leaving the penthouse behind, Alex was immediately cornered by his aunt Shannon, who was waiting for him in the hallway. She had overheard his discussion with Diana, and wanted to talk to the man about some personal matters.
Why was Shannon staying at a casino during a weeknight? Because now that her little sister owned a series of casinos, she had pressured the woman into allowing her into the High Roller Club as a way to meet wealthy men, in an attempt to find a proper husband for herself.
Of course, throughout the night, she had unconsciously compared each and every one of these men, most of which were in their fifties and sixties, to Alex, and found herself thinking that they were completely lacking. Which ended up in her not speaking with any of them, despite her initial intentions to do so.