Yay, more stuff about me being a self-centered asshole!

So, this time... Well, actually, I better put in a disclaimer here. This is going to sound really stupid, so keep reading if you'd like a laugh.
Anyway, Eliza (she's a close friend of mind) was good friends with Mike (I didn't/don't know him). She asked him to do her Debutante with her (in case you don't know, it's a french tradition where 16-year-old girls invite guys to a formal party, traditionally to advertise their marital availability). Now, this is a big day in a girl's life over here; a lot of the time it's not far away from a wedding in the amount of effort that goes in.
Anyway, Eliza was going with Mike (I was jealous). But, she told me today he dumped her for another girl. She was so upset because she was really looking forward to it, and now she can't go (I'd go with her but she's in a year level above mine, which is the prerequesite for entry).
So I decided to give Mike a piece of my mind. I did this via text so I didn't get the shit beaten out of me (he's about 8 foot tall and has the muscle mass of a silverback ape). I told him he didn't deserve to kiss the ground Eliza walked on; she's a beautiful, amazing girl and she deserves better than him. I did this because I somehow thought this would be gallant and that I would be protecting her.
I told Eliza this and now she is angry at me for acting without her consent. I do concede that in hindsight it was a poor choice, but when she told me he'd made her cry I seemed to be unable to control myself. Now she doesn't want to tell me about her problems anymore, which stresses me because I like to help her through them.
I honestly don't know why I'm writing this here... I guess I just need to get it out of my system.