I didn't realize you had the whole trip covered... I thought just the plane/concert tickets. In any event... I still wouldn't see the big deal even if you didn't have the whole thing covered...
As for the selfish argument... when she calls you selfish, you look her in the eye and say, "I have no doubt you feel that way."
Mrs. HD: "I feel taken advantage of..."
HD: "I'm really sorry you feel that way."
In so doing, you acknowledge you have heard her, you acknowledge her POV, you are being respectful and empathetic, but you are not backing down, nor are you necessarily agreeing with her.
This is only going to be a big deal if you continue to treat it like its a big deal. Stop.
I agree with Lil that you need to be more informed about your finances for all kinds of reasons.
Hope you have fun on your trip, even though it is a month or so away.
