Is OTHER wrong in the post ? POST : WIBTA?  Without getting into a super long story:  My mom got pregnant when she was 18, I was born, mom and biological dad never got married, I was adopted by my stepdad when I was 18 months.  I had a great mom and dad growing up, never had anything to do with my biological dad.  As I got older (26) I wanted to understand my history a little better, found my biological dad in Colorado, and went and met him for all of about an hour. Nothing special occurred during that hour, but it was good to get the meet and greet out of the way.  As part of my research, I discovered that I have 3 half siblings via my biological dad (all are now adults). My biological dad also told me that his wife knew about me and that it was not a big deal (which I kind of agree with, this was before him and his wife got together, 26+ years ago, etc.). Several years later I reached out to him explaining that I would like to communicate with his adult kids and kind of just let them know about me and give them a "hey I exist, if you're ever curious about me feel free to reach out" note.  He got super weird and shut that down very quickly.   Bottom line, I have the names and addresses of at least 2 of my half-siblings. They are adults.  WIBTA for bypassing biological dad and just sending them letters? I know I wouldn't think its a big deal if I received something like that (I would be intrigued and want to know more about my half-sibling), but maybe I just can't see it from their perspective.   If this helps, it isn't like I'm a creepy guy.  I am a successful attorney, married with two kids, served in the military, love dogs, hate communism, play the guitar; you know all the good red-blooded American stuff. 