Recently I was on a job hunt. I applied for several positions, one of which was at Company A.
Simultaneously, I heard through an old coworker that Company B, where I used to work as a consultant (I was well liked there and left on good terms) needs some resources.
I contacted my ex-manager at Company B and told him I was currently on the job hunt (and disclosed that I was indeed interviewing at other places), and would be interested in coming back to Company B as a full timer. He said he would be happy to try to open a position for me and extend an offer.
After that, I received a great offer from Company A.
If the offer from Company B is good, I can handle turning down the offer from Company A without feeling too awkward - it was an open job application and these things happen.
However if the offer from Company B isn't that good and I'd rather go with Company A. If this happens I will feel as if I wasted Company B's time and basically spit in the manager's face by making him jump through hoops and still rejecting him. I feel like this would be a burned bridge with him for sure, and I admire him greatly.
What's the best way I can turn down Company B in this situation?
Issue Update
Thanks for all the help - even though I'm only allowed to pick one best answer, all of the answers helped guide me. I had a phone conversation with the Company B boss where I said I appreciated that he made me a generous offer but I received another offer that was too good to refuse. He (of course, being a professional guy) said he understood.