First off if this man in your life has suffered SA in his child hood the only real thing you can do is show him that you are there for him when and IF
he wants to share that info with you. And that you will not judge him. Telling someone that you have been abused is one of the hardest thing a man can do. The teddy bear is a good thing. Kind of cool if you ask me.
having an affair is not what I want to be doing
ummmmmmmmmm HELLO.......is he forcing you to "having an affair"? If the answer is no then you want to be doing it.
I am not looking to destroy a marriage
you may not be looking but you are. This is a married man and you have been sleeping with some other womans husbond for 7 years. Wonder how long you and him will be before he finds anther one like you. You should change your name to "Harm" because you are not providing Harmony for this man's life. In fact you are probley doing harm to him. Helping him see that keeping secerts is just part of life. Shame on you. You say you love this man, what about his wife? You make no mention of her. You say you have known him for 30 years. Which leads me to believe you know his wife and if they had kids then you have seen his kids grow up and start lives of there own.
Now this is a place to get support on issues due to SA, but you have to take the good with the bad. I am sure that you will find ways to help this man and help yourself at the same time. But when you come in here talking about abusing his wife please be ready for the backlash.