1. She’s classy well put together eye candy for his businesses on his arm 2. Kate’s witty, sharp, and can hold a conversation about business or "business" and not embarass Stefano 3. She has a lot of "experience" in past career to keep an older been around the block a few times gentleman with happy endings… 4. they both have a lot of history together and with that history comes mutal respect for each other. I see it as a win-win for both of them, although Kate is a black-widow spider when she wants to be and Stefano can be a devil – so if the two ever get tired of each other – I want a front row seat.