Dwindling circle

We had a poker night at work last night. We've had them off and on for the past 6-8 months. It started with 7-9 people. Last night there were 5. I got a set of chips for Christmas last year, and asked around various co-workers and friends that I can tolerate, to see who might be interested. My first thought was to have a very small buy-in, say 5 dollars or so. Small enough that it wouldn't break anybody to play, and small enough that tempers wouldn't get wild, and a fixed amount so that nobody could lose more than that in a night. That idea kinda went out the window right away. We found that we were serious enough players that we could play with chips and no buy-in and be real with the 'money'. It's more fun that way. It's always been by invitation only. There are several people who work here that we can't stand, who would definitly horn their way in if they knew about it. Well, over the past half season, we've lost two of our regulars. Last night kind of had a strange vibe. One of the ladys got in a funk and went quiet for a while, and never would talk to us about why. She eventually opened back up and was her usual vibrant vivacious self, but she never explained what or who set her off. That always bothers me. I'm kind of paranoid now about my relationships with these people. In the past, I've done and said things that have strained and fractured one particular relationship. What hurt most was that the young lady didn't tell me at the time that I was being an asshole. She wrote me a letter some days later, telling me the new ground rules for our working relationship. And yes, she's one of our poker group too. One of our group moved out of state to a new job. One got fired, and is no longer welcome in the building, though we've met at one of our apartments on one occasion, we usually meet at work. But, as I said, the usual comaraderie was not quite what it used to be, and it broke up a little early. Still a fun time, but not what it once was.
Then again I'm going into one of my funks, and it could have been just me.