Advice on a tricky social situation?

The guy I’ve been seeing (we’ll call him J) and I decided to “officially” call ourselves boyfriend and girlfriend yesterday. After the news got out, I received a text message from another close (male) friend of mine, we’ll call him N. He said congrats, but also said “I’m not gonna pretend I wasn’t interested in you, if you couldn’t tell. I just hope this doesn’t change things between us.” He’s acting a bit sullen now.

I also don’t want things to change between N and me, because he’s one of my closest friends and I really enjoy his company. I feel bad that he may have been hurt as a side effect of J and I getting together. I’m worried that he may feel betrayed: I may have been sending him signals I didn’t mean to send by being my usual friendly self. And N and I play music and sing together sometimes, which is just a naturally intimate activity in a way.

I didn’t realize N was interested in me. I thought maybe, but I just wasn’t sure, and I also had a weird (apparently incorrect) gut feeling that he might be gay! In hindsight, I think I was pretty dense for not realizing, though. He has put a lot of effort into our friendship…and that fact just makes me feel worse about hurting him.

Also, J and N are good friends, and will be sharing an apartment next year, so I certainly don’t want to cause any strife between them.

I’m meeting N for dinner tonight (soon!) at the campus dining hall. I want to show him that he hasn’t fallen on my list of priorities.

Do the wise jellies of fluther have any tips for me?