I also don’t like to talk openly my feelings very much. You can work around that in a couple of ways. One way is to not ask him how he feels about it, but instead say how YOU feel and ask for his input. “Sometimes I worry that I’m slighting you when I arrange social things for your sister, because I know you don’t get into the social thing so much. I’ve been wanting to arrange some things that are more in your court. Is there any place you’ve been wanting to go?”
The other pointer I’d have, is to bring it up in a very casual way, and keep the conversation casual. Otherwise he might feel embarrassed because, even with ADD, he’s still 14 and heart to heart talks with Mom are not cool when you’re 14. And he’s a guy. I heard a joke on TV once by a female comedian who said that the one self defense technique that women really need to know is that if you’re threatened by a guy who intends you harm, you should look into his eyes and say, “Honey, we need to talk,” because there isn’t a male on the planet who won’t turn and run when he hears that! So I’d suggest just at some random moment, saying something like, “Hey, can I run something by you?” That way, it’s not a big deal and you’re not asking him to talk about his feelings. You’re just casually asking for his input on your problem.
One of two things will come of it. Either he takes the bait and gives you some ideas, or he says, “Nah. Is there any pizza left,” and walks off, carefully avoiding looking “not cool,” but secretly pleased to know you’re concerned about his feelings. No way you can lose 🙂