Shari, we live in a different world now. The stigmas of te past are just tat - in the past. Or they should be.
easy child should know you and what sort of person you are. Use this to your advantage.
When you talk to easy child, just say to him, "I love you and always have. You are on this earth because I chose to love you even before you were born. I have also done my best to be honest with you. When you began asking about your father, I did not say he was dead, or anything else. I said I would tell you when you were older. The story was complicated and it was also painful for me to tell it. However, the truth is there."
I would tell him everything form your side, be as charitable about his dad as you can by saying, "He was young, and blokes tat young are generally jerks in this sort of situation. And to him, I was probably nothing serious. I was vulnerable because I had been raped and nothing had been done about it. He would have seen me as easy, and not understood that I was such a mess as far as my self-esteem was concerned. I felt a failure, until I had you. Then I knew I had something good in the world. But I never hid you. You only have my word for this, but I think after all these years, you should know how much faith you can place in my word."
Then leave it at that. Maybe make it clear tat you will say this only the one time, unless he brings it up again.
If he forms a relationship with his father, then over time he will get to know what sort of person he is.
But one thought - is there a chance that either of your parents played a part in freezing out this young man? Sometimes parents interfere and we're not aware of it.
My mother-in-law had an ex-boyfriend whose romance faded into good friendship. She had told her fiance about her ex-boyfriend and together they planned to continue the friendship, as a couple. Ex-boyfriend was moving house, she knew, and was going to let her know where he was when he got settled. He knew she was getting married, both of them had moved on emotionally.
But when mother in law & father in law came back from their honeymoon, mother in law asked her mother, "Did the letter from ex-boyfriend come?" and her mother told her that he was to be of no more concern to her, and she had burned his letter to completely remove temptation.
Ex-boyfriend never wrote again, probably thinking her lack of response meant her new husband disapproved of their friendship after all. Or maybe ex-boyfriend did write again, because mother in law & father in law lived with her parents for the first five years or so of their marriage. Her mother always got to the mail first.
However, from what you have described, this perhaps isn't too likely.
Shari, you had a really raw deal and of course PTSD has got to be on the agenda. At least you have easy child 1 out of it.
So something wonderful came out of it after all.
Marg