I am sorry you are feeling the anger. Be angry, work through it, and then move on.
If going with H doesn't sound like much of a vacation, then don't go. But I advise being very non committal at this time as you don't want to give him an answer based on your emotionalness (ie anger.)
I would like to add that I see it as a positive that H invited you to come along...my H doesn't include me in anything family related as he doesn't want to give the kids "the wrong idea". IE, that we will be and do as a family.
The anger will pass, and I am sure it will come back again. Feel everything when it comes. You got this Miz.
BombOctober 2012- OW 11/28/12 -H still denies Separated 11/29/12 Own place 12/12/12 Confessed OW/EA/PA 2/2/13 Oct 2013 - I knew I was done Jan 2014 - Anticipating the rest of my life