I wouldn't let something like not wanting to disappoint keep you from pursuing an opportunity that could change your life (I think someone already mentioned opp

I wouldn't let something like not wanting to disappoint keep you from pursuing an opportunity that could change your life (I think someone already mentioned opportunity cost). That being said, if you know anyone else you know and trust, and whom you would vouch for, given the skills required for the internship and who would take the internship, then I'd recommend him to the employer if they still need someone to fill the position. This is a practice I learned from being in a band. Booking agents hate when you cancel, but love you for it if you provide another band to play in your stead. Granted, I know this is much easier to do with a band than with an internship.