Am I being unreasonable?

My husband had a trip for work this week, and he was near Glacier Park. Glacier is one of my favorite spots, and I wanted to take him there. Last year, he went there with his female co-worker, and I was very hurt. They went back again - and again without ME. He's shocked that I'm even more hurt, and keeps asking why I'm still mad. They had separate rooms, and I fully trust there's no cheating. Not physically, anyway. But I feel betrayed in my friendship with him. This was an important place to ME, and he's gone twice with another female. He's still on the business portion of the trip, and I'm just still so dang angry. Am I wrong to feel betrayed, ignored, like I don't matter?