I've never been that interested in the royal family. I remember reading that Charles never gave up is relationship with Camila after he married Diana and that Diana spent a lot of time alone while Charles was spending time with Camila. And I remember how well both boys carried themselves at the funeral of their mother which was a compliment to how Diana raised them.
Choosing to marry someone who "wasn't approved" of by that bunch was unhappiness waiting to happen. Harry is not the first to leave.