I love the pose you were aiming for, because it's so loving and gentle. If it had turned out better, it would have been an instant fave!
Unfortunately, the anatomy is horrible. Braeburn's leg is mangled incomprehensibly and he has no mid-section apparently. The attempt at giving him a more humanoid upper body didn't quite pan out either. His arm is strongly juxtaposed beside Soarin's and the muscular definition is awkward even for a human arm. With the position of Braeburn's head, instead of looking as if his neck is arched, it appears as if he doesn't have one. His tail looks like the end of a large paintbrush, not a pony tail.
Soarin is much better off, in fact he looks good overall (although the one wing that we see isn't defined that well and looks far too long) but there isn't enough room for his neck when leaning back like that, so it seems to be melding into Braeburn's body. We should be seeing more of his throat jutting out, if he's simply resting it there, even from this angle. I also have it in my head that as Soarin leans back, Braeburn should probably be crouched forward, not sitting upright, but that particular detail may be personal preference. The rest of my complaints are not.
I wanted to like this. I really did. I hope that you brush up on your human and animal anatomy, then study the way the ponies work in the cartoon a little more, and try drawing this again. It's a great idea... It just didn't work out this time.
i don't really draw anymore, but thanks for the detailed feedback. to tell the truth, i totally forgot about soarin's wings until i had finished everything else, so i had to add it in at the last minute...