I've got good news and bad news for you!
The good news is that Layton will be one of two love interests in the post release DLC, Made Marion: Light and Shadow (the other has not yet been revealed).
The bad news is that you might not like him quite as much about five minutes after the end of the Sherwood demo.
And if it helps, Marion and Geoffrey's marriage would not have gone well if she'd made it to Nottingham on the Sherwood route. They need the events of the Nottingham Route in order to be compatible.