You know, after watching the first run-through with your actors, you know what my impulse was?
To make them have a pillow fight.

I don’t know why, but I think that would have gotten him into his body in a way I would have liked and would have connected her to him in a way I would have liked.
They already had, and were continuing in class to, explore psychological & emotional understanding.  Their bodies just were not quite hooked up to all that –especially his. (And you may have noticed that when his body started to get connected, the acting got better.)

That just flashed through my mind and I thought I’d mention it to you since you were asking about possible things to do (re: physicality) and I answered before seeing the actors you were working with and how they were responding to the material and relating to each other.

(And, not, of course, that it would have been more ‘right’ than anything else, it just occurred to me and I know I hadn’t mentioned that possibility, and I thought you might appreciate it as an exercise.  
It’s not one that’s appropriate or specifically helpful a lot, but here, yes.  And, no, I’ve never known any director to do it (other than me), but who knows, maybe someone has.)   It’s the kind of thing I make actors do in my acting classes.  I just make things up to stretch them in directions I’d like them to explore – never knowing how much it will work – usually I’m pleasantly surprised.  There are probably several other things that would have worked in this case.  And what keeps it all ‘safe’ & appropriate - is, I think, my honest concern, as a teacher, for their growth.

As a director, I think that translates into having honest respect & appreciation for the actor as a person and as an artist – and if you really feel that, they’ll lap that up and do anything for you.  Even trying things they don’t understand or agree with.  Which is also, by the way, the best way to find out if you need to change your vision.  Or not.