First, I should say I don't know if either one of you is "right" or "wrong", just different.
That said, personally, I do a lot better when I know what's going on with my partner than I do with uncertainty. Like Maleficent said, I'm not going to ruin our relationship by micro-managing every moment, but I would like honesty and a bit of prior knowledge even helps. Where is the line between casually talking about what he's doing and micro-managing? Only the two of you can decide that. I was going to type "You don't need to know exactly what he's doing if he doesn't want to tell you." After reading it back, I do agree with that in part, but if you build up a situation where he doesn't want to tell you what he's doing most of the time, I'd find that to be a problem.
My partner and I have agreed telling each other generally what we're doing is a good middle point we can compromise at. She'd like a little less info and I'm for 100% openness, but we're working together on it. For safety reasons, I like to know generally where she's meeting her date and if they change locations, but that can get a bit police state in a hurry. I trust her and will dial back my patriarchal instincts before they injure the relationship.
Also, don't assume that privacy is the same as hiding or lying. During my 14-year marriage my wife never understood that there had to be some privacy for the sake of my sanity...and we ended up getting a divorce. I wasn't lying or hiding when I wanted to keep a journal of my thoughts or wanted to spend time out and around the city alone doing absolutely nothing other than thinking and browsing stores and libraries.
Me - male, 42, poly, straight, in a serious relationship with Audrey, also casually dating.
Audrey - female, 20, poly, pansexual, also casually dating.