Sorry, I am just reading this post, but I have a story that is kind of opposite, just to put things in a different perspective. My husband and I got married in July of 2003. I had one semester of college left, and was about to graduate in December of 2003. We had been together since November of 1997, no breaks - nothing. Neither one of us had ever given the opther one reason for doubt, but thought still cross our minds . . .
I was working on a project in one of my classes with a guy my husband had never met. We had both procrastinated to the last possible minute onthis project and had to get it done. My husband was working on a Saturday, and I called my classmate and we decided to work on the project. We said we would meet at school, but the more we thought about it that was stupid because we lived about 10 minutes from each other but about 20 minutes from the school, so I met him at his apartment.
Absolutely nothing happened, besides the project of course (which we did get an A on) but I had previously told my husband we were meeting at the school (because that was the plan, I wasn't lying to him) but we changed at the last minute. I told him when I got home that I had been at the other guys apartment, and he didn't really say anything. A few days later, after stewing about it, he called me at work and told me he wanted a divorce.
I was shocked - It had been totally innocent, nothing happened, I love my husband and would never cheat on him and I just couldn't see what I did wrong. But the fact was, he is kind of insecure, at it really bothered him. We ended up working it out, thankfully, but I finally had to realize that even though it was totally innocent, he was not comfortable with it. In order to make him comfortable, I made sure I was never in another situation where he would question what happened. There is a thin line of trust there, but I would rather give up this one "freedom" so to speak, then put the stress on our marriage.
So I guess what I am saying is that from my experience it is a two way street. You both need to be comfortable in order for things to work. There is a good chance nothing happened, that they really are just friends and that nothing ever will happen. But if it bothers you, he needs to be aware of that and if he really cares about you, put your comfort above anything else. As long as your requests aren't too unreasonable (which they don't sound like they are) this should not be a problem. It kind of sounds like that is what he is willing to do. I do believe trust is important, but it doesn't hurt to have a little reassurance too.