I worked as an SE intern for about a year at a large local company, before leaving to finish my degree. I left the company on excellent terms, and made it clear that reapplying to the company upon graduation was an option, and my boss expressed a great desire to rehire me upon graduation. Shortly after I left, my old boss reached out to me with a full-time job offer at the company.
Though I do like the company, the team, and the work they do, I also want to open up some other options and apply to some other places, namely in a different geographical area. Considering how highly my old boss thought of me and my work, and how he was more directly involved with me and my work than my coworkers, I feel like he would be an excellent reference. However, since he is so interested and involved with the rehiring process (he himself sent me the job offer), I feel it would put him in a very uncomfortable and difficult situation.
Would it be inappropriate to ask him for a reference?