What do Atheists do?

Are you familiar with meetup.com?
Some meetup groups are religious, some are new agey, some are for fun, some are for exercise. There are all sorts.
My questions is what do atheist groups do?
I can understand pagan groups getting together, meeting in a forest, and worshipping a tree. I really don't know what pagan groups do, but that's what I imagine they do.
Maybe Christian groups sing worship songs or gather for Bible study.
And artistic groups could paint together or do a group trip to a special exhibit.
Tennis lovers get together and play tennis. That makes sense.
What what do atheists do when they hang together?
Talk about what they don't believe. That's a lot of energy to spend for something they don't believe.
They don't worship together because they don't believe in God or the magical powers of a tree, or am I missing something?
How does nothing bind you together?
Do you rage against Christmas and that you get the day off, sometimes with pay?
Are you planning festivus? If so, what are you celebrating?
If you're part of an atheist group, please let me know what you do when you meet up.

Personal Experience

I have some questions:
1) Does Felix Baumgartner have a wife or a child? Is his mother still alive? What worry he must cause people. He's hardly the first person to do something to worry the womenfolk.
2) Are there any third party presidential candidates? There must be somewhere. Luckily, I only rec'd one annoying political email.

Attended a talk at Church about Vatican II because it's the 50th anniversary of the start of Vatican II. The lecture was a bit light, but the speaker said one thing that stuck with me. He said the Holy Trinity was not just doctrine to the early Christians, but they were the personal experiences of early Christians.

I'm on the search for real friends who want to meet and talk in REAL LIFE and not just rely on Facebook because I don't do FB.