Parents unsure what to do

I have a17yr old son who broke up with a girlfriend of 2 yrs. Prior to the breakup, we had booked a vacation and my son invited her to go along. They have been broken up for a month now, talked a little since then, and we depart in 30 days. My son says he really doesn't want her to go on vaca with us which I understand, as it will be awkward. He needs and will tell her in the next few days, but what I am not sure of is..do I go along with him so I can talk to her parents as well? We paid for the vacation completely so there are no funds they will lose out on. She will be so upset and probably very mad. HELP.

This is not ideal and probably tough on your son. I personally wouldn't speak to her parents, just speak to your son and if he really doesn't want her to go, respect that and urge him to tell her ASAP. He won't thank you for speaking to her parents and really it won't help. Its bad that you will lose out financially but these things can't be avoided sometimes. I would focus on going on a great holiday with your son. As he get older he may not go on many more holidays with you. Good luck