I've been with my boyfriend for a couple of years. We both have kids and don't live together. We see each other most weekends. We text or speak every day.
We saw each other at the weekend, after a few hours I noticed he hadn't smoked so I asked him about it. He said he'd decided to give up. He's not a heavy smoker but this is good news. I asked if it was the first day and he said he started on Monday, 5 days before. So at no point during those 5 days did he think to tell me. I said I was really annoyed that he hadn't told me but he doesn't see why it's a big deal. I just find it weird that he hasn't bothered to tell me something important.
This isn't the first time he hasn't told me about things going on his life. Some have been more important, some have been less important. But we are in a committed relationship where we talk about the most menial of things so why not tell me about the more important things?