Once and for all, this has to be addressed.

If Ben was any more like Dean, I'd suspect cloning.

Lisa denying that Dean's Ben's father is very suspect. Why so much protest?

Let's end this mystery and put all the cards on the table.

I could see Lisa wanting to protect her son, but someday he's going to ask about his father. This is a perfect opportunity for the big reveal.

Why did any sort of romance exist? That's not Wednesday. She's above that.