Here's my two cents. Bottom line is that she's wanting to do something even though she knows it upsets you. As you put it, she's putting you in a no win situation. So be calm, but honest. I would say something to the effect of "You are well aware of my feelings on the matter. However, the decision is yours. Do what you need to do"
Don't let her make you into the bad guy. Let the decision be hers. She wants to go despite knowing how it hurts you. That's the real issue. Unfortunately, it's not something you can do anything about. It's something she needs to work out on her own. But you need to be prepared to deal with the fact that she may choose to go. You can't get angry if she makes the "wrong" decision. This is where boundaries come in. If this is a boundary for you, then it needs to be set with very specific and very real consequences that you are truly willing to follow through on. If you are not prepared to do so, then you may have to deal with the fact that she will continue to see the band and the guy in question. But again, you cannot do so with anger.
This is where we LBS have to be enormously patient while our MLCers act stupidly.
"Love me when I least deserve it, for that is when I need it the most"
M18 Me39,H42 D16 Bomb 1/10 Moved out 3/10 OW 6/10 H wants to R,OW gone 11/10 H moves back 5/11 H wants to wear rings again 9/11
