I'm quite a bit older than all of you and I've relapsed several times in my life. A couple of weeks a ago I was right there, a shattered mess. It can happen. You get through it. Beating yourself up about it emotionally only adds to the guilt and shame and makes it harder to deal with the underlying problems that started it all.

A lot of times men are kind of taught to repress their own emotions. They get told to "man up". Especially if he hasn't had any experience with self harm, he might have been worried or scared but not known what to say or how to handle the situation so he just withdrew and hid any reaction he might have felt. Talk to him about it. Or maybe write him an email telling him why you did it and how you feel about his reaction. Maybe he can express what he's feeling better that way?