To add my two cents to this - I'm adopted and having people refer to anyone other than my adoptive parents as my "real" parents is a huge, huge, huge button pusher for me. They are my real parents, the egg and sperm donor are nothing to me, absolutely nothing (unless one of them is leaving me money because I'm mercenary like that).

Having said that, I think that many adoptive and/or step children are accepting of the social convention of using real parent to mean the biological parent. It's because a shorthand way to avoid the intricate discussions about relationships. I know that I've done so on those occasions when I really don't want to have the fight about how offensive I find it. So in this story it didn't bother me that Hotch would use that expression because I can accept that he would use the terminology simply due to ease of use.

Of course, if you want to get all internet psychologist about it, Hotch using the term real father could also reflect the depth of the betrayal for someone who is blood and who is supposed to give his protecting his child turning around and causing harm. Thus, the real term emphasizes that the man who did that was one who was betraying one of nature's deepest laws. It also elevates the man who was his father by choice and who chose to act in the way that the bio-dad should have.

Or I could go back to thinking about the pretty pretty men having the hot hot hot sex. That's good too.