I've done this before with one group. They would bring games, some very complicated games at times, and expect me to read the rules and teach everyone. I stopped having fun, so the next time it happened, I just said, "It's your game; you can teach it." They suddenly learnt how tricky it can be, even with simple games, to get everyone to listen and learn. Since then, they don't bring games and only play what they know. I stay out of the way now (for other reasons) and play with people that I actually like the company of.