Dean's only impression of Ross was, by and large, that he was moneybags.
Take his modified sports car, for example. Dean had asked the forensics department; the President's car, in terms of bulletproofing, was probably at a similar level—perhaps even inferior. This was because the glass on Ross's car wasn't thick, implying the materials were more advanced and acquiring them through money and connections alone would be extremely difficult. So, even when Laura approached him several times to re-establish contact, Dean ruthlessly rejected her. He didn't want to get into trouble.
Ross didn't live in Laura's villa; that was just a birthday gift he had casually given her. Given Ross's character, he probably wouldn't take back what he'd given away, even if he knew he had been cuckolded.
