Really. A "true" brother? Hmmm.... I'd be a bit torn about that as well. Especially after so many years.
Personally (giving unsolicited advice), I'd respond. After all, life is too short to distance yourself from family (or friends) unless it is a completely destructive relationship.
This is probably a little personal for this site so I'll keep the details to a minimum. Went to Facebook, something I rarely do.
I got a friend request from one of my brothers that I haven't seen in at least 15 years. That f#cked me up. I saw pictures of my
mother for the first time in years. That f#cked me up also. She died over ten years ago. Man, I don't know if I'm happy or sad.
Defintely confused.