I took your advice this morning after he stayed out until 1 or 2 pm Sunday night thinking. I basically paraphrased what you said:
I think you might try to have a relaxed conversation with him and tell him that you will not place any expections on him as far as intimacy goes and that you don't want him worrying that you will misinterpret his actions (or lack of actions) as he mentioned before. Be careful not to say anything about his parents. That is a touchy subject for him and could easily lead to a fight. However, you could tell him that you just want to be able for both of you to have a relaxed atmosphere at home and not expect a lot from each other and just try to feel comfortable.

His response was me too. I told him that I will be alright - we'll all be alright. He asked something like are you saying you all alright or agree (my memory is shaky - I was nervous on this one). I just said I've told you how I feel about things. No matter what we'll all be fine. It will be devestating but we'll all get through it. You're gonna do what you have to do.

He mentioned something about maybe he shouldn't go to the lake next week. I asked why and he said something like he was worried about everyone. I told him to go if he needed to get away.

Tonight when I walked in the door after working out, my older son said have you heard from Dad? I said no. He said I've tried to call him but it just goes into voice mail. You'll be proud of me because I didn't call him. He finally called and said he was talking with his Aunt. I'm actually glad he's finally talking to someone about all this. Here's the kicker - I'm close to his Aunt as well. So you know I'm dying to call her. It's taking all my willpower not to call her!

I think if the stress level around here is reduced I'll be better able to manage my anxiety and practice the last resort technique.