.Andy said:Just have him read lots of books. Being well read will increase his vocabulary and mental tone. Nothing could be sexier than that!
Good advise IMO. At 126 US pounds at 5'6" he is plenty slim enough in most peoples eyes. And I would think that if there is any "flab" on this guys body, it is a matter of toning. He may never be "ripped", but it sounds as if he has the right stuff for many of us to only wish for.
The sad fact is that the media today has filled our heads as to what the perfect body is to look like. The truth is that genetics plays a part also.
We need to start to realize that not all of us are built for 6-pak abs. I have known professional dancers that nearly killed themselves (both male and female) to have that "perfect" body that directors "wanted".
I do have to question the desires of the OP in wanting to "tone" up their BF. Why, other than to fit their own desires of a physical image.