From What I've read, you seem troubled that your husband has made online friends with people who share a common interest with him. I'm also gathering that you are concerned that one of those friends is female. Let me ask you this --- if all his online friend were male, would you still be troubled?
Does he spend so much time chatting online with people that when you weigh it out, it turns out that he spends more time with them than he does with you? Would you feel the same way if the friends lived locally and they got together in person?
When he chatted with the woman and told her he couldn't talk because you were sleeping---were you actually asleep?
All that said, from what you wrote, it seems like he isn't hiding anything from you. He has given you his passwords which tells me he doesn't mind if you were to check the sites he visits. My husband knows my email passwords and I know his. Even though we each can look at the other's email, we don't do it unless invited by the other to look at a specific email.
So...I'm guessing you are feeling insecure because he has some interests that are different from yours. That's perfectly normal in a marriage---in fact it is very healthy to have some interests that are different from your spouse's.
I have virtual online friends---some are in different countries. It's been a positive outlet in my life---especially these days when it seems (at least where I live) difficult to make and keep friends. Many of these women I chat with have been very supportive when I've vented about some problems. I, too, have been there for them.
In fact, I have exchanged private messages with male posters in other forums. It always has been about the forum subject---nothing more. I've told my husband about these chats, too. In one forum I'm always signed in. If he wanted to, he could see this for himself. He, too, has chatted with men and women about work related issues in various forums.
But I digress. Unless you think your husband has gotten to the point where he ignores you totally, then I say until you have reason not to, just trust him. It sounds like he extends the same trust to you.
If you think that playing this game has become an addiction for him, then you need to confront that issue. Point it out to him that he is spending far more time on this activity than he is with you. See what his reaction is. If he agrees to spend less time playing these games so that the two of you can have more time together, then that's good if he follows through. If he is in denial, then look into some counseling for the both of you.
Good luck to you!