What am I?

Here's an odd one.

Ron's sister had 3 sons.  One of them had a son.  Now that boy has a girl pregnant.  What the heck are Ron and I, to the baby?

But it gets weirder.  My own mother had my brother when she was 13.  My sister at age 14.  Then she had me at age 32.  I have a nephew two years younger than myself.  But wait, HE has kids.  At least 3 that I know of.  One of them may have kids.

I also have a niece a few years younger than that.  She has kids.  They are still, kids.

That's not even counting the steps.