Thanks guys...My BF and I talk about everything quite a lot. We don't live together yet but our future plans include that. His son's mother is Bi-polar, um quite lazy, feeds his son lots of junk food (like McDs etc) though I was careful to avoid talking about that stuff in front of his son. She may be uh, how she is but she is still his Mommy and that won't change, I respect that. I haven't yet met her but I'm sure that day will come soon enough.
I'm not a totally strict nutjob but if I think his son is going to do something dangerous or bad I think it's ok for me as an adult to tell him "no" and he doesn't seem to mind me doing it, either.
I also was teaching his son how to knead bread dough, how to spread cookie dough to make bar cookies and some other things. He was keen to learn all about those things and takes instruction amazingly well. The kid doesn't act bratty like some 6 year olds do, he's laid back, like his daddy.
I actually really like his son, we share a love of swimming (he let me toss him around the public pool and we went off the diving board/slide etc.) I won't ever have my own children, aside from expensive medical intervention (too old now anyway) so maybe someday I can be his pseudo-mom or something, if he wants.