Do you know if they tend to be more open with your t? You could ask her to help you approach the situation, working to get trust involved, and coming up with solutions. If they're upset and not open about doing it, having your t there as a mediator might help them to feel more comfortable owning up to it. It sounds like there may be issues that are occuring, but they don't trust you to help them deal with it? I could be completely off of course, as I dont' know you guys. But getting them to trust you enough to talk about issues before hurting the body could be beneficial.

Good luck, let us know how it goes on Wednesday. Enjoy boxing :P Sometiems it helps if you imagine your oponent is whatever is bothering you, and you can let yourself get angry and do something about it. Very good strategy for processing hurt and anger, something I'm not comfortable doing in many cases :P

IJ